細胞的密碼
比利時生物學家阿爾伯特·克勞德（Albert Claude）由於對細胞結構和功能組織前所未有的發現而獲得諾貝爾生理學或醫學獎。 他的論文中指出人是細胞殖民地的行動者(a colony of cells in action)，細胞無時無刻不在整合運作。細胞創造我們,掌控我們, 也造就了我們, 他們才是我們真正的主人。
而自然禪黃老師因為自身遭受的身體各種細胞的突變，深受其苦。因此開始對細胞做深入的研究。
癌細胞基因開關、細胞記憶、ＤＮＡ修護冥想、能量場、弦理論、三爻和螺旋程式，這些來自細胞分子層次的靈性療癒，透過科學實證研究，不再只是冥想中的形上學，而是確實和我們心念緊密相扣的實相。
人生難免會遇到低潮、困境、挫折，
如果你正處在低潮中，
其實，你並不是孤立無援，
有一群好友，一直忠實沉默的陪伴著你，
那就是──你身上的60兆個細胞。
你可能從未察覺細胞的存在，但，細胞其實有很多神奇的靈性現象，像是：
‧細胞之間，可以互相溝通。
‧細胞能聽到「禱告」。
‧細胞可以說服彼此，用同樣的節奏跳動。
作者桑德拉‧巴雷特（Sondra Barrett, PhD），在本書生動的寫出許多細胞的美麗故事，例如，生理學家潘諾貝克做過一個實驗，他請學生寫出不曾告訴別人的祕密。最後，他發現，揭露內心隱私的學生，不僅免疫力改善了，壓力荷爾蒙也降低了。
細胞的靈性現象，不只如此而已，舊金山綜合醫院心臟科住院醫師伯德，曾研究「禱告對加護病房的心臟病患者，有沒有實際幫助」，但病患並不知道有人在禱告。研究結果顯示，受禱告祝福的人，心臟突發狀況與併發症，比沒受禱告的病人還少。
此外，作者曾發現，培養皿中的每一個心臟細胞，一開始都以不同的節奏跳動，不可思議的是，心臟細胞跳動的節奏愈來愈接近，最後完全趨於一致。
其實，細胞隱藏的力量，就像一個宇宙那樣巨大，只要你願意傾聽細胞的聲音，就能重新找回自身的無窮潛力，坦然度過人生的每一個挫折。
Cell Intelligence
http://www.basic.northwestern.edu/g-buehler/htmltxt.htm
雷尼約翰（John Renni）在2017年12月28日《科學美國人》所發表的一篇文章
《要小看单细胞的细菌，它们可能真的拥有“智慧”》
https://huanqiukexue.com/a/qianyan/shengwu__yixue/2017/1228/27700.html
Intelligence is a fractal property or/and an emergent property: ...Intelligent ecologies contain intelligent populations, which contain intelligent organisms, which contain intelligent cells, which contain intelligent compartments, which contain...and so forth.
智能是分形屬性或/和湧現屬性： ...智能生態包含智能種群，智能種群包含智能生物，智能生物包含智能細胞，智能細胞包含智能隔室，其中包含......等等。
CELL INTELLIGENCE
SUMMARY.
MINDSET
Depending on the direction in which one reads the next sentence, intelligence is a fractal property or/and an emergent property:MAIN HYPOTHESIS
A. Cells control the movement of every part of their body.A. 細胞控制著身體各個部位的運動。
Cell movement is not random.. The cortex consists of autonomous domains ('microplasts') whose movement is controlled by a control center (centrosome). Microtubules mediate between the controll center and the autonomous domains.細胞運動不是隨機的。細胞皮層是由自主域（“微質體”）組成，其運動由控制中心（中心體）控制。細胞微管介導控制中心和自治域之間。（細胞微管是細胞骨架的一個組成部分，遍布於細胞質中。）
B. The control center detects objects and other cells objects by pulsating near-infrared signals.控制中心通過近紅外信號的脈動檢測物體和其他細胞物體。
Cell have 'eyes' in the form of centrioles.. They are able to detect near infrared signals and steer the cell movements towards their source.
APPROACH
For the past 2 decades I have applied essentially two lines of reasoning to examine whether cells are intelligent. They can be summarized in the following statements:
A. If cells can measure space and time, they must be able to derive abstract data from physical signals.
Space and time are not physical objects with which cells could interact, but they are the pre-condition of all physical objects. If cells can measure space and time variables such as angles, distances, curvatures or durations, they must have derived these abstract quantities from the physical objects of their environment. Chapter 2 will use the apparent symmetry and identity between the branches of the phagokinetic tracks of dividing cells (an example is shown below) to argue that cells are programmed to measure angles and time durations.
B. If cells have eyes, they must be able to order and integrate countless signals.
Images are the ordered set of a huge number of individual data. If cells are capable of generating an image of their environment and react to it, they must be able to order a large number of signals and integrate them into a response action. Chapter 3 will present the evidence that cells use centrioles to 'see' all objects around them that emit or scatter near infrared light. The figure below shows one of the examples of this amazing ability of cells.
Introduction.
An operational definition of the intelligent cell.
First a disclaimer. My work over the past 2 decades did not intend to join the ongoing efforts of philosophers, logicians and computer scientists to find a universal definition of intelligence. On the contrary, it did not question the common assumption that everybody can tell a mindless, mechanical gadget from an intelligent machine, and proceeded to ask which of the two categories apply to a living cell. Clearly, there are many different levels of intelligence, but I believe that most people consider a machine mechanical and mindless if its actions either do not seem to respond to signals or else always show the same set of reactions. On the other hand, we expect an intelligent machine to responds to signals in a large variety of ways, especially if the signals are unforeseeable, and if its responses offer solutions to problems which were transmitted by the signals. Usually, this means that the intelligent machine contains at least 2 different machines, one which it mindless and carries out some mechanical labor while the other collects and processes signals and controls the action of the first.
Therefore, I went ahead using the following operational definition of an intelligent cell. An intelligent cell contains a compartment which is capable of collecting and integrating a variety of physically different and unforeseeable signals as the basis of problem-solving decisions.
Are there reasons to think that cells are intelligent?
The prevailing wisdom of modern biology has it that cells are immensely complex, but rigidly operating chemical machines that derive their operating instructions internally from their genes and externally from chemicals and electrical signals emitted rigidly by other cells. Unable to believe that any machine can be designed that contains an instruction library which anticipates all the mishaps and glitches of a billion years of evolution without crashing over and over again, I began more than 2 decades ago to search for signs that the cell was actually a 'smart' machine. In other words, I looked for experimental evidence that cells contained a signal integration system that allowed them to sense, weigh and process huge numbers of signals from outside and inside their bodies and to make decisions on their own.
One of the reasons for my disbelief was the sheer size of the organisms that cells built out of themselves. Organism like us are 30,000 times larger in length and and we are not the biggest. Keep in mind that the cells of a gnat are not smaller than the cells of a whale. The whale just contains a lot more cells. How could they build such a huge range of organisms without the ability to override any permanent instructions in order to solve unforeseeable problems on its own?
Anybody who ever built anything bigger than himself knows what frightening surprises it can bring to exceed the dimensions of actions and objects with which we are familiar. The Sears Tower in Chicago is 'only' 300 times larger than the body of its architects. Ask the architects and construction companies who solved the legions of surprise technical problems whether an architect rigidly programmed to respond mechanically could have built it! Then try to build something 30,000 times larger, i.e. a building which is 25 miles tall with a rigid and mechanically operating robot!
Under what circumstances would a cell reveal that it is 'intelligent'? I thought that the best place to start searching was the field of cell movement. A moving cell has to operate its own body in sophisticated ways and, in addition, may have to navigate in space and time while dealing with numerous unforeseeable events, such as encounters with other cells and other objects that its genome could not possibly have anticipated.
I think that cell motility, indeed, revealed cell intelligence. This website highlights some of the experiments and offers the images and the arguments that support the claim of cell intelligence. The left side of the screen guides the visitor to the various topics, subheadings, images, bibliography and a platform of discussion that reflects responses of visitors to my e-mail address.
Does it matter if cells are intelligent?
1.If cells are intelligent, molecules and their genes would be the 'collaborators' or even 'slaves' , but not the 'masters' of the life functions of cells.
We have all accepted this in the case of organisms. For example, consider the function of an organism like me to make sounds with his throat. Everybody takes it for granted that there is no gene that programmed the words that I speak, but that the information processing speech center in my brain makes the molecules in my throat act and interact when I speak them. Yet, when it comes to cells we tend to believe the opposite: Daily, biologists claim to have found new genes and molecules that act and interact to produce this or the other cell function. If cells are intelligent we would have to rethink all the cause-and-effect chains from genes to molecules to cell function that we believe today to be true.
2. If cells are intelligent, medical treatment may involve 'talking to cells [See ref 17] rather than to flood the organism with pharmaceuticals as we do today.
If cells are intelligent, they are capable of integrating physically different signals (mechanical, electrical, chemical, temperature, pH, etc.) before they generate a response. Integration of physically different signals is only possible if each is first transduced into a common, unifying type of signal. The unifying signals are then integrated and subsequently re-transduced into the response action. For example, all the different kinds of signals that we integrate in our brain are first transduced into unifying electrical pulses, called action potentials, before we integrate them. Finally, we return the same kind of signal, namely electrical response pulses from our brain to the e.g. muscles which re-transduce them into mechanical actions.
If cells have an integrative system, it must also use unifying signals which it links and gates by genetically inherited, cell-specific logical rules before it responds. (Of course, the unknown cellular unifying signals will not be electrical signals like action potentials. Cells are far too small for that. ) In other words, if the cells are intelligent they must use some kind of language which we can learn to imitate.
All diseases are ultimately healed by cells. Doctors 'merely', aid the cells of their patients to do their job. Just imagine, the powerful medicine doctors might practice in the future if they can literally 'tell' cells in their own language what they want them to do! For example, cancer cells might be 'told' to stop growing or at least may be 'summoned' to a certain place on the skin where surgeons can easily scoop them out. Cells at the wound of a lost limb or eye may be 'told' to regrow it. They did it once. If we learn the right 'language' maybe, they can do it again.
3. If cells are intelligent, an organism would be the ecology of a huge population of intelligent individuals.
We tend to believe today that our bodies are highly organized buildings composed of cells which we consider to be dumb miniature machines. Even neurons are treated as complex, yet rather dumb signal switching gadgets. However, if each cell has a certain intelligence to make decisions on its own we would have to reconsider this concept, too. In this case, we would have to look at the structures and functions of our bodies as the result of the interaction of a huge population of intelligent individuals. Possibly, we would have to learn to look at our bodies much the way we consider the complex structures and actions of cities and nations as the result of the actions and interactions of huge numbers of individual people. And 'huge' hardly does justice to the number of cells that make up an organism. For example, one human body has more cells than there would be people on 1000 planet Earths. Also, of course, every cell is a much less intelligent part of a body than a human is part of a city or nation. Still, many of our rather mechanical explanations of body functions would have to be re-examined.
TABLE OF CONTENTS
Anatomy of the intelligent cell
(Selected features)
_________________
We believe that the following cellular compartments are essential for the intelligent control of cell movement [See ref 10]
Plasma membrane and cortex.. They correspond to the 'skin' and the 'musculatur' of a cell. One can break this part into small, autonomously moving units, called 'microplasts'. [See ref 8].Their very autonomy implies that cells contain some kind of control system which prevents the autonomous units from moving randomly and independently of each other. Otherwise the cell body would presumably go into uncontrolled convulsions or else freeze up altogether.
Bulk cytoplasm:Mitochondria, other organelles and intermediate filaments. This compartment comprises the actual cell body excluding the nucleus. It corresponds to the 'guts and inerds' of the cell body. Its main cytoskeletal component are the intermediate filaments, although microtubules travers this compartment everywhere. It contains the organelles, such as lysosomes and mitochondria.
Nucleus. From the point of view of the 'intelligent cell' the nucleus is the main library. It contains the blueprints and instructions that have evolved over one billion years of evolution, which tell the cell how to operate, how to rebuild itself (including its 'nerves' and 'brain') after every cell division, and how to act and interact with other cells as they build and maintain an organism.
But there is more. Its gene control systems handles huge numbers of signals that arise from within the nucleus and from its outside word, the cytoplasm. It seems to be structured as a hierarchy of levels of genomic instructions. Starting with genes which constitute the most basic level, transposons may belong to a meta-level in the sense that they represent instructions for genes. There may be a meta-meta-level of 'itinerons' that determine the destinations of transposons, and so forth. In short, the nucleus, far from being a 'dumb' library of the intelligent cell, is clearly an intelligent system in its own rights. We may be seeing here the first glimpse that intelligence is a fractal property: Intelligent ecologies contain intelligent populations,which contain intelligent organisms, which contain intelligent cells, which contain intelligent compartments, which contain...and so forth.
Centrosphere: Centrioles and radial array of microtubules. From the point of view of the 'intelligent cell' the centrosphere is the 'brain' of the cell. Analogous to our own bodies, it projects the 'eyes' in the form of a pair of centrioles. Likewise, its 'nerves' correspond to the radial array of microtubules connecting the centrosphere unbranchingly with the cellular 'musculature' contained in the cortex.
TABLE OF CONTENTS
Symmetry of sister cells
Why cell movement may appear to be random.
For many years people have believed that cell migration is random, and many still do. There are understandable reasons for this belief. For example, the complex shape changes of migrating cells are quite confusing in the short run. In order to recognize the non-randomness of cell migration much longer observation times are required. Long periods of live cell observation in turn require keeping the cells alive and moving inside a temperature controlled, sealed observation chamber under the glaring lights of a microscope. Often, researchers placed too many cells in the microscope field, which added the complexities of cell-to-cell collisions to the situation. Finally, it is always tempting to call something 'random' even if it is merely 'unpredictable' by the knowledge of the time.
Phagokinetic tracks
Many years ago I found a new technique that allows cells to migrate in the controlled, protected and and dark environment of their normal culture incubator for days and weeks, while the experimenter can still observe their movement. This is possible because the technique, called phagokinetic tracks works like a cloud chamber in which the cells leave tracks of their movements in a carpet of tiny gold particles on their substratum. The phagokinetic tracks can be viewed by scanning electron microscopy like in the illustration above, but it is more convenient to use darkfield light microscopy like in all the illustrations below.
The related tracks of sister cells
When a cell divides, the track of the mother cell branches as the 2 sister cells go their different ways. If there are no other cells around which might disturb the branching pattern, it shows an amazing property: In 40% of the cases the track of one sister forms the mirror image of the other. Below is an example of such symmetry that even pertains to the tracks of the 'grandchildren'.
Not only are the tracks of sister cells related, but the shapes and internal architecture of their bodies (i.e. their cytoskeleton) appear as symmetrical or identical as their tracks are [See ref 1, ref 2 ]. This suggests that the programs that determine the future movements of the cells are implemented by building and re-building the inner architecture of the cells [See ref 3 ]. .
Significance for cell intelligence:
If cells are able to program directional changes at certain times in their life cycle they must be able to measure angles and time durations. This implication is strengthened by their ability to override these programs in sophisticated ways if they collide with other cells, encounter guiding lines or participate in group migration.
TABLE OF CONTENTS
Collision behavior
Colliding cells seem to rebound like colliding billiard balls
Sister cells can only move along symmetrical or identitical tracks if they do not run into obstacles or other cells. What happens if they do collide? Do they literally stop in their tracks, or do they run around erratically? Neither of these possibilities occur: The cells seem to bounce off each other like colliding billiard balls. The figure below shows an example of the tracks of 2 colliding cells that produce remarably symmetrical paths in the vicinity of the impact area For more examples see ref 2.
Rebounding must be reprogramming
In spite of the appearance of the tracks, the collision between 2 cells cannot be elastic like the collision between billiard balls. Cells do not fulfill the minimal requirements of an elastic collision whose hallmark is the conservation of momentum and kinetic energy. Their extremely slow crawling movements resemble moving through molasses because it dissipates all momentum and kinetic energy. More importantly, they have no defined, hard surface from which they could bounce off. The sequence below shows how complex the shape changes are and how tenuous the contacts are if an epithelial cell (on the left) collides with a fibroblast.Note: the fast moving cells in the experiments described here are always fibroblasts. Most epthelial cells migrate very little, and if they collide with other epithelial cells they remain together.
Significance for cell intelligence:
TABLE OF CONTENTS
Cells detect subtle guidance
Guidance is not chemical in nature
It has been known for decades that scratches or ridges on a surface cause cells to line up alongside and follow them. Any surface material can guide cells. No special chemicals are required. In fact, glass, plastic, gold and other typical surface materials are chemically completely inert. The cells cannot have specific receptors for such materials on their surface. Also, it is not necessary for such guiding lines to be chemically different from the rest of the surface. Besides, the necessary serum in the fluid medium around the cells instantly coats all surfaces with proteins. So, all surfaces are practically made of serum proteins. Yet, the cells detect the presence of guiding lines.Cells are not forced mechanically to accept guidance
Are these guiding lines mechanical obstacles that force the cells to move in certain directions?.In order to answer this question I put cells on a glass surface which was very thinly coated with gold. Then I wiped scratces into the gold film exposing the glass underneath. Cells like to walk on glass and gold alike. Furthermore, the gold was much thinner (300 A) than the thickness of a cell (30,000 -60,000 A). In other word there was not much of a step height between the glass and the gold surfaces. Yet, as shown by the straightness of the track below, the cells were guided quite well by these very subtle guiding lines.
Significance for cell intelligence:
TABLE OF CONTENTS
Guidance: Not by force but by information
Anything that changes from a fast road to a slow one without thinking must obey a 'law of refraction'.
The law of refraction received its name from optics, but it applies much more universally. It makes no difference whether we observe a beam of light, an avalanche of snow, or a herd of cattle that move from one kind of terrain to another where they have to change speed. They all change direction as if they were refracted by the interface. The figure below illustrates the principle.
Cells do not obey a 'law of refraction'.
Whatever mechanical force is supposed to explain the guidance of the cells (e.g. differential adhesion, different local pH which may alter cortex activity, etc.), it will ultimately have to change the speed of the cells. Let us assume, that the guidance we observed on gold surfaces with glass 'roads' scratched into them, is due to e.g. a higher adhesion on gold than on glass. Consequently, cells crossing over from glass to gold should slow down while obeying a law of refraction. Accordingly, their tracks should turn towards the perpendicular line (see figure below). On the other hand, if gold would accelerate the speed of the cells, their track would turn away from the perpendicular line. However, either way it is certain that a cell coming from the lower right quadrant has to advance into the upper left quadrant after crossing the border between gold and glass.
Significance for cell intelligence:
However, if the troop maintains its direction upon changing into the field, and even turns and follows the curb, we know that the mechanical forces of traction do not explain the action of the soldiers now or earlier when they followed the road. Instead, we can infer that they were driven by an interplay between endogenous instructions and exogenous signals that were processed by their signal integration systems. I think, the same logic applies to cells that do not obey laws of refraction. In the case of the soldiers we know that their actions are dictated by their brain. In the case of cells, I suppose, we have to conclude that they have one.
TABLE OF CONTENTS
Cells probe their surroundings. Gathering of global information.
Cells do not lose guidance at intersections between 'roads'. Instead, they examine their options
The cells in our guidance assay were not forced to follow the 'roads'. Therefore, we concluded that they were able to detect at least 2 points on the guiding 'road' and derive from their location a new heading. How powerful is their data processing method? Can 2 intersecting 'roads' throw them off course, because the cells would not know which 2 points to connect for a new heading? In order to answer this question, we offered the cells a grid pattern of intersecting 'roads' that were produced similar to our previous guiding assay. In the figure below, the grid pattern can be seen as a disturbance in the gold particle coat that we used to track the cells.
Significance for cell intelligence:
TABLE OF CONTENTS
Group migration
Cells can migrate in groups
Most epithelial cells migrate very little in tissue culture, and if they collide with other epithelial cells they stay together. However, this does not mean that a group of epithelial cells is also a slow mover. For example, I found that PtK1 cells can migrate in groups that are much faster than the single cells. As illustrated in the figure below, the tracks of single cells are much shorter than the tracks of a group migrating for the same length of time. In addition, the figure on the right hand side shows one of the migrating groups in scanning electron microscopy to illustrate that the group does not fuse the cells into one large syncitium, but conserves the individuality of the member cells.
Group migration is not a tug-of-war
The simplest explanation for group migration of cells would be a tug-of-war: The strongest cells pulls against the others and thus determine a resultant direction.However, this explanation cannot apply in the case of migrating PtK1 groups. Obviously, if cells in a group pull in opposite directions, they will slow each other down. Thus, the group can never move faster than its members migrating alone. In contrast, PtK1 cell groups are faster than their members.
There is another important difference. The direction of a group in a tug-of-war would fluctuate soemwhat randomly depending on the superimposition of opposing forces from one moment to the other. As shown in the live cell sequence below, that is not the case for PtK1 groups, either.
Significance for cell intelligence:
TABLE OF CONTENTS
Autonomous movements of cytoplasmic fragments
The co-ordinated shape changes of migrating cells
When whole animal cells move, different parts of their bodies carry out different movements. For example, the so-called leading front may ruffle while the trailing end, the so-called tail retracts. When a cell makes a turn, it simply produces a new pseudopodium into the new direction. The figure below shows the typical example of a mouse fibroblast that undergoes dramatic and concerted shape changes as it turns a tail into a front and vice versa. In this way it makes a turn without actually rotating its body as a whole.
How can cells move different parts of their bodies differently? The answer came when we found ways to isolate viable fragments from the periphery of cells which we called 'microplasts'. They were able to move independently. By controlling the actions of each such domain the cells can control the movements of different parts of their body. But, of course, it means that the cells must have a central control system to do that. [See ref 8]
Microplasts
Microplasts are fragments of cells that remain alive for many hours.They come in various sizes. The smallest contain about 2% of a cell volume and consist mostly of cortex surrounded by a plasma membrane. Their movements are autonomous, but restricted to the universally observed shape changes such as spreading, attaching, ruffling, blebbing, waving of filopodia etc. Unlike whole cells they cannot move their entire body to another location after they were forced to round up and respread. This procedure destroys all directional properties that might have been left in their bodies from their parental cell. Microplasts cannot restore or create directionality of movement.
Ruffling microplast
Significance for cell intelligence
a. The cell must contain a motor control system that controls the movments of its entire body. It determines when and where its numerous motile domains are allowed to carry out any of their built-in movements. Otherwise, these domains (i.e. cortex domains from which the microplasts were formed) would exercise their autonomy and render the cell incapable of any directional, purposeful movement.
b. The inability of microplasts to restore or create directionality of their movement suggests, that directionality of movement is the product of a higher level of control. Since the directionality of movement responds to obstacles and other unforeseeable events in the path of a moving cell this high level control appears 'intelligent' (i.e. signal integrative and decision-making).
TABLE OF CONTENTS
Are centrioles the 'eye' of the cell?
Eyes map the directions of signal sources in a one-to-one fashion.
A cellular eye will hardly look like anything that we have ever experienced in our macroscopic world. Before trying to identify it, we have to define in very abstract terms what an eye is. Consider the schematic of a human eye in the figure below.
The best possible design for a cellular 'eye' would look like a pair of centrioles
It is not difficult to show that the best possible design for a cellular eye would look like the pair of centrioles shown in the electron micrograph below [See ref 14 ].
Centrioles are able to map the direction of light sources in a one-to-one fashion.
Assuming that each slanting blade of a centriole- absorbs or deflects light of certain wavelengths,
- carries a photoreceptor at its base (see red spots in the figure below)
- the lumen of the centriole is opaque for the light.
If the first centriole measures the 'longitude' of the source, the second is oriented perpendicular to the first in order to measure the 'latitude'.
Centrioles come in pairs that are oriented perpendicular to each other. From the point of view of the theory presented here that makes a lot of sense. Each centriole can only map the angle of the source in a plane perpendicular to its axis (e.g. the longitude). In reality, however, the light sources will be distributed in three dimensions. Therefore, we need a second centriole at right angles to the first in order to determine the latitude of the source, too. The figure below illustrates how a pair of centrioles measures the longitude (red lines) and the latitude (yellow lines) of a light source.
Cellular 'vision' can only make sense for near infrared wavelengths
One can guess which light, if any, cells would not use for their 'vision'.- UV, or gamma-rays because they would be mutagenic.
- Visible light, because inside the body of large animals like whales, there is no visible light (But there is, of course, infrared light equivalent to the the body temperature).
- Infrared light with wavelength above 10 [µm], because the black body radiation peaks there and makes everything glow with the same high intensity.
- Infrared light with wavelength above 1.5 [µm], because cells live in water and water absorbs this light heavily.
Problems: angular resolution,diffraction, absorption, and signal-to-noise ratio
Angular resolution: So far the angular resolution AR of the device is AR=360°/N (N=number of blades= number of photoreceptors).In view of the centriole structure we used as number of receptors N=9 which yielded a resolution of AR=40°. In other words, the cells could not tell sources apart if their directions are closer than 40° which would give cells only a very crude map of their locations. However, as explained in ref. 14 and in the Appendix, there is a very simple and elegant way to make the angular resolution continuous by adding a pitch to each blade. And, indeed, actual centrioles have blades with this pitch. Pitched blades may pose a problem for the requirement of one-to-one mapping (see Appendix).Diffraction: How can a blade of 70 [nm] width cast a shadow for near-infrared light that has a much larger wavelength of 800 [nm]? Should light of 10 times the wavelength not simply diffract around the blade? Yes, and no. If the photoreceptor is placed right behind the blade, there will still be a shadow even if the wavelength of the light has a much larger wavelength. However, if the photreceptors would move away from the blade, the amplitude of the diffracted light would rise rapidly and reach it. This little known fact about diffraction can easily be verified with a metal plate playing the role of the shielding blade, and a small transistor radio that plays the role of a photoreceptor. AM stations transmit at frequencies of 100 kHz corresponding to wavelengths of 300 [m] which are much larger than the metal plate and the transistor radio. Still, one can locate the station by pressing the radio against the back of the plate while turning the plate into different directions.
Absorption: How can a blade of only 20-30 [nm] thickness absorb or reflect enough light to cast a shadow? It can if it is metallic, i.e. if it had a high electrical conductivity. For example, a layer of 10 [nm] gold, aluminum or copper is quite opaque, because it reflects incident light very efficiently. Therefore, it will be important for the above theory to test whether centriolar blades or any other microtubular arrays have high electrical conductivity. Human technology has produced already a number of organic polymers with high electrical conductivity. Maybe, nature knows the same trick.
Signal-to-noise ratio: No matter what specific light sources the cellular 'eye' is supposed to detect its near-infrared wavelength is also a component of the black body radiation that is emitted everywhere by virtue of the ambient temperature. Therefore, the ratio between the signal and the background noise must be very unfavorable for the signal detection. In similar situations human engineers resort to a very effective method. They modulate the signal intensity with specific pulsation frequencies which allow the detectors to ignore the background noise as it does not pulsate with a regular frequency. Therefore, we expect the cellular near-infrared light sources to pulsate.
As pointed out in the Appendix, pulsating sources are also required if cells have to distinguish between 2 sources that are located in the same sector of size AR=360°/N (N=number of blades= number of photoreceptors)..
Significance for cell intelligence:
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Cells detect microscopic infrared light sources
Experimental setup to test the hypothesis that cells can 'see' near-infrared light sources.
The experimental setup created a microscopic light source out of a single, small latex beads by aiming a narrow beam of near-infrared light at it. The beam intensity was pulsating at rates of 1 per second. The plastic bead scattered the light towards cells nearby, but released no chemicals that could attract the cells. The heating of the bead on the order of 1/10,000th of a degree was negligible.The cells were kept in a live cell chamber with careful temperature and pH control. In order to be able to see the cells in the microscope the entire chamber was illuminated with low intensity, visible light of 600 [nm]. The behavior of the test cell was recorded by video and infrared sensitive CCD cameras.
Note: In the recordings shown here and in other sections the phase contrast images of the beads appear white. The irradiated bead is surrounded by a halo of light because the camera is looking directly into the infrared beam. The scattered intensity received by the cells is approximately 1/1000th of the intensity seen by the camera.
Extension of surface projections towards the pulsating light sources.
We recorded more than 800 cells and found that a statistically highly significant percentage of the cells extended new pseudopodia towards the plastic beads if they scattered near-infrared light. Often, they displayed very unusual motile behavior, like the cell shown below which turned 180° in order to reach the light source.
Absence of heat effects:No convective currents near light spot.
The interpretation that the test cells are capable to detect the light sources at a distance may meet a major objection: The infrared beam may heat the medium as it traverses the observation chamber. The heated medium will rise and thus generate convective currents that flow continuously toward or away from the particle. Consequently, it may not have been the light which guided the cell extensions to the light sources but by the direction of these convective currents. However, we recorded several hours of video sequences which showed that small latex particles inside the chamber near the infrared beam perform normal Brownian motion without any directional component to indicate convective currents.Absence of chemotactic gradient:Particle pick-up in spite of medium stream towards the particle.
Another objection may claim that the beam produces chemical changes in the medium or at the irradiated particle which set up a chemo-attractive gradient for the surrounding cells. Therefore, we let medium flow through the chamber (speed appr. 2.7 mm/s) and selected situations where the medium streamed from the cell towards the light spot. If there was a chemo-attractive gradient, its material should be driven away from the cell and the cell should not be attracted to the light spot. Nevertheless, the several test cells moved towards the light spot.Significance for cell intelligence:
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Infrared detection is not phototaxis
Cells reach out to a second light source while exposed to the high intensity of the first that they reached
One may try to explain the cellular detection of infrared light sources by simple phototaxis. In other words, it seems possible that the test cells attracted to the light extended the new surface projections towards the area of highest intensity. Cellular 'vision', on the other hand, would require a considerable more complex response, namely the ability of the cells to make out several light sources individually.In order to distinguish between these possibilities we offered the cells 2 light spots of equal intensity. If the attraction of the test cells was merely phototactic they would either steer exactly between the light spots while being attracted with equal strength to both. Alternatively, should they ever stray off the midline they would experience increasing intensity from the closer light spot and approach it while ignoring the other which appears the weaker the closer the cell approaches the first. In contrast, we recorded many video sequences which showed that the cells were able to extend first to one and subsequently to the other. The following 2 live cell recordings show examples of this finding.
Significance for cell intelligence:
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Location of the cellular 'eye'
Cells cannot reach out to a light source if their center is illuminated with the same light (center-irradiation).
According to our hypothesis the centrioles mediate the extension of surface extension towards infrared light sources. Therefore, it should be possible to 'blind' cells temporarily by shining the same light into their center that illuminates the scattering particle nearby with a second beam of the same intensity and wavelength. Such treatment does not cause any detectable damage to the cells as indicated by their normal motile behavior once the light to their center is turned off. The experiments showed, indeed, that cellular extensions towards nearby light sources are inhibited as long as its center is irradiated by a second beam of the same wavelength, intensity and pulse frequency.Cells remain able to reach out to a light source if a spot next to their center is illuminated with the same light (peripheral irradiation).
In contrast, cells remained capable of reaching out to the light source nearby if the second light beam hit them a few micrometers away from the cell center. Both results together suggest that the cellular infrared 'eye' is located in the cell center and must be one of the cellular components that are located in the cell center but nowhere else. The obvious candidates for such structures are the nucleus, the Golgi-apparatus and the centrosome. The following experiments exclude all candidates except the centrosome.Centrosomal location of the cellular 'eye' (exclusion of nucleus as 'eye'): Cells can still reach out to a light source after enucleation.
In order to test whether the nucleus was required for cellular infrared 'vision' cytoplasts were produced by incubation in cytochalasin B followed by centrifugation. Among 20 experiments with enucleated cells 4 picked up the light scattering particle. Since only one was needed to disprove the assumption that the nucleus was the infrared sensing mechanism, we did not carry out a larger number of experiments. Therefore, only the Golgi-apparatus and the centrosome are left as candidates for the infrared 'eye'.
Centrosomal location of the cellular 'eye' (exclusion of the Golgi apparatus as 'eye'): Cells can still to reach out to a light source after destruction of their Golgi-apparatus.
In order to test whether a functional Golgi-apparatus was required for cellular infrared 'vision' we incubated 3T3 cells overnight in 0.15 µM monensin. This treatment vesiculates their Golgi-apparatus and inhibit their Golgi functions. Yet, among 9 monensin-treated cells we found 4 that reached over to the particle. The results suggest that the ability of 3T3 cells to detect and extend surface projections to infrared light scattering particles nearby does not require the presence of a functional nucleus or Golgi-apparatus. Therefore, only the centrosome remains as an exclusively central cell organelle that may contain the infrared sensing component(s) of the cell center.Significance for cell intelligence:
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Can cells see each other?
What could be the biological function of cellular infrared 'vision'?
As shown in the flow diagram below, our work up to this point seems to link cellular infrared 'vision' with animal development which depends critically on cell migration .
Therefore, we suspect that the infrared 'vision' of cells plays a role in development.
There is an additional reason for this conjecture. Animal cell migration is very slow and animal development occurs simultaneously everywhere in the embryo. What, if a migrating cell makes a mistake and ends up in the wrong place? It cannot stop the development everywhere else, turn back the developmental clock and start from scratch. Therefore, it seems good engineering to provide the migrating cells with the means to 'look ahead' towards their spatial goals.
How far should a cell look ahead? In a developing embryo any spatial goal is a moving target. If it takes a cell 6-10 hours to reach this goal, it would probably no longer exist because development may have changed the area around the goal too much. Since an animal cell needs about 1.5 hours to cross its own diameter of appr. 20 µm its spatial goals should be no further away than 4-6 cell diameters or 80-120 µm. Indeed, our experiments showed that the cells ignored microscopic light sources that were further away than about 60 µm [ ref 13. ].
Cells detect each other at a distance.
It stands to reason that the major kinds of spatial goals of cells in an embryo are other cells. For many years I oberved that approaching cells reached out towards each other from a distance, as if they 'saw' each other. The figure below shows a remarkable example.
Cells react to each other across a film of glass.
In order to test whether such cell-to-cell encounters were mediated by some chemicals, I separated cells by a thin, but chemically impenetrable glass film. The figure below shows a Hamster fibroblast sitting on one side of the glass film (Let us call it the 'A'-face).
Significance for cell intelligence:
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Are microtubules the 'nerves' of the cell?
Another line of arguments to support microtubules as good candidates for cellular 'nerves' comes from experiments that interfere with microtubules: If anti-microtubular drugs are given to the cell it can still move all parts of its body, but the remarkable coordination of the typical shape changes is lost. This led to the following question. Are any signals, indeed, propagated along the microtubules to the cell cortex in response to pulsating near-infrared light? If so, how can they be detected?
Experimental strategies to identify changes of microtubules during a putative signal transmission.
Signal transmission is unlikely to drastically change the microtubule structure.
If microtubules, indeed, conduct such signals one could hardly expect them to cause structural changes of the microtubules drastic enough to be visible in a microscope. Such an expectation would be analogous to the search for structural changes of the optical nerve every time the retina transmits images to the brain. Nevertheless, for several years I tried but failed to find any direct effects of pulsating near-infrared light signals on microtubules or other cytoskeletal components.Signal transmission may alter the effectiveness of anti-microtubular drugs.
Consequently, I took an indirect approach. If the putative signals themselves had no direct effect on the structure of microtubules, I hypothesized that they might enhance or diminish the effects of some other agent that was known to change the structure of microtubules. For example, it seemed possible that the traveling signals were strong enough to alter the speed of disassembly of microtubules which were exposed to an anti-microtubular drug. Therefore, I measured the stability of cytoplasmic microtubules in the presence of nocodazole while exposing the entire cell culture to pulsating near-infrared signals.Disassembly of cytoplasmic asters ('DCA') of CV1 cells.
Therefore, I wrote a program to measure the microtubules in a cell while they were disassembled by the anti-microtubular drug nocodazole. The figure below shows a typical example of the way the program turns the fluorescent patterns of microtubules (panel a) into a set of labeled pixels (panel b) that can be counted.
Significance for cell intelligence:
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Are mitochondria the natural cellular light sources?
The possible role of heme-related molecules in the reception and emission of near infrared light
The heme group is derived from the porphyrin molecules which is essentially a network of 36 conjugated bonds arranged in a flat disk.
Chlorophylls and cytochromes as models for the absorbers and emittors of near infrared light.
All chlorophylls contain the heme group as the chromophore which absorbs the light energy used for photosynthesis. Some of the chlorophylls such as bacteria-chlorophyll absorb at the same near infrared wavelength which most attracctive for the tissue cells in our experiments. Therefore, bacteriochlorophyll may be considered as a model for the unknown pigment molecules in the centrioles of the light sensitive tissue cells that absorb the near infrared light.Heme proteins may also serve as models for the unknown emitter substances of the pulsating infrared light because there is no principal reason why the quantum-mechanical absorption mechanism could not also be an emission mechanism. For example, I have shown recently that bacteriochlorophyll is able to fluoresce in the near infrared range [See ref 18]. As mentioned above,mitochondria contain practically all the heme proteins of tissue cells. Therefore, they appear to be excellent candidates for near infrared emitters of cells. It is also likely that they would emit the light in pulses whenever they discharge a load of ATP molecules that they have synthesized in the course of their normal function, namely oxidative phosphorylation.
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The best design for a cellular eye is a pair of centrioles
Cellular eyes cannot use lenses to locate light sources.
Cellular eyes cannot resemble the eyes of familiar organisms in the macroscopic world. For example, cellular eyes cannot not use lenses, because the typical cell size of approximately 10 µm is too small. Obviously, such lenses would have to be much smaller than the cell itself. Therefore, let us assume that the lens diameter is 1 µm. Lenses can only focus light whose wavelength is smaller than about 1/1000th of their diameter. Otherwise, the light would simply diffract around the lens and ignore it. In other words, cellular lenses can only work with light whose wavelength is smaller than 1/1000 µm = 1 nm, i.e .with X-rays. This means that there are no materials from which to grind cellular lenses because no materials exist which are able to refract X-rays to any extent.Cellular eyes cannot compare signal intensities to locate light sources.
Many bacteria are fast swimmers. They can afford to do many trial-and-error runs in order to find the source of a chemoattractant. As long as the signal strength increases they continue their tack; whenever it decreases they tumble and change direction. Animal cells cannot use the same trick. Compared to bacteria they are extremely slow. By the time a cell has found a target in this way, the embryo would long be finished everywhere else.There is a further problem. Due to the ubiquitous and violent thermal fluctuations the world of cells is extremely noisy in every respect. Whatever concentrations or intensities a cell on a trial-and-error run may wish to compare from place to place, they are all very unreliable. To be sure, a mathematical average over the signal strength could eliminate the fluctuations, however, in practical terms it would not work.Imagine yourself in a howling hurricane trying to average the strength of coffee aroma in the air order to find your cup!
The ideal eye has no directional preference.
Consider a signal source (e.g.a source of light or anything else that propagates along straight lines, and let us design the ideal eye for it. Unlike our own eyes which can only see in the foreward direction, an ideal eye would have no such directional bias. Consequently, it would be rotationally symmetrical like the circle on the figure below.
'Blinds' can accomplish the one-to-one mapping of source directions
Considering that neither lenses nor intensity sensors can help us eliminate the ambiguity of the above source mapping device, we may try to attach blinds to each receptor that are able to block the signal. If we attach them radially as shown in the figure below we reduce much of the ambiguity, but not all.
Each 'blind' must be curved
In the previous figures the blinds were drawn slightly curved. It was necessary, because straight blinds could not prevent the ambiguity of the mapping for certain directions: Signals from a source in the very direction of the slanting blinds could still reach 2 receptors as shown on the left hand side of the figure below.
In order to work in 3 dimensions, the design has to be a cylinder
The above design can only work as long as the sources and the 'eye' that we have designed so far are both located in the same plane. If the source rises above the plane of the 'eye' as shown below, the blinds can no longer protect the receptors, and the 'eye' fails to map the source direction.
In order to map longitude and latitude of a source we need 2 cylinders perpendicular to each other.
Even the cylindrical design of the 'eye' can only map the angle of the source in a plane perpendicular to its axis (e.g. the longitude). Therefore, we need a second cylinder at right angles to the first in order to determine the latitude of the source, too. The figure below illustrates how a pair of centrioles measures the longitude (yellow lines) and the latitude (green lines) of a source.
Pitched blinds achieve continuous angular resolution.
So far the design guarantees that each source direction can irradiate one and only one receptor. However, it does not guarantee that each receptor can detect only one source direction. In other words, the angular resolution of the design is rather crude: If it has N blinds, then the angular resolution is 360°/N.Unfortunately, one cannot increase the number N at will in order to achieve finer and finer resolution because each blind has to have a certain minimal thickness in order to absorb or reflect the signal. But there is a much more elegant way to refine the resolution to such a degree that it is practically continuous: One may pitch the blinds as shown in the figure below.
Back to the drawing board?
Pitched blinds may offer continuous angular resolution, but can the 'eye' still map source directions in a one-to-one fashion? After all, each source can reach the receptors of 2 consecutive blinds. Therefore, 2 sources in consecutive sectors should be able to reach receptors attached to the same blind.It is true, 2 sources can reach receptors on the same blind, but at different positions on the cylinder axis. Pitch or no pitch, any receptors at a specific position on the axis of the cylinder can still be reached by only one of the sources.
A problem arises, though, if the 2 sources are located in the same sector, and some of the receptors of the same blind are irradiated by both at the same time. Obviously, in this case the cell cannot tell the sources apart unless they differ in at least one characteristic. It would be rather simple to distinguish between different sources if their emission would pulsate at a specific frequencies. In this case the cell could compute the location of either source by relating only receptors that receive the same pulsation frequency.
Pulsating source intensities would also offer a solution to the problem of increasing the signal-to-noise ratio that is particularly important in the thermally very noisy world of cells. Indeed, the experiments show, that cells are able to detect pulsating near-infrared light sources but not sources with constant intensity.
Significance for cell intelligence:
- Centrioles are built as a pair of cylinders perpendicular to each other.
- In cross-section they have slanting blades.
- The angle of the blades is such that the backward elongation of each blade intersects the foot of the previous one.
- Each blade is slightly curved.
- Each blade is pitched .
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Bibliography
(Selected articles)
1. Albrecht-Buehler, G.: Daughter 3T3 cells: Are they mirror images of each other? J. Cell Biol. 72: 595-603, 1977
2. Albrecht-Buehler, G.: The phagokinetic tracks of 3T3 cells. Cell 11:395-404, 1977
3. Albrecht-Buehler, G.: The phagokinetic tracks of 3T3 cells: Parallels between the orientation of track segments and of cellular structures which contain actin or tubulin. Cell 12:333-339, 1977
4. Albrecht-Buehler, G.: The tracks of moving cells. Scientific American 238:68-76, 1978
5. Albrecht-Buehler, G.: The angular distribution of directional changes of guided 3T3 cells. J. Cell Biol. 80:53-60, 1979
6. Albrecht-Buehler, G. and Bushnell, A.: The orientation of centrioles in migrating 3T3 cells. Exp. Cell Res. 120: 111-118, 1979
7. Albrecht-Buehler, G.: Group locomotion of PtKl cells. Exp. Cell Res. 122:402-407, 1979
8. Albrecht-Buehler, G.: The autonomous movements of cytoplasmic fragments. Proc. Natl. Acad. Sci. U.S.A. 77: 6639-6644, 1980
9. Albrecht-Buehler, G.: Does the geomentric design of centrioles imply their function? Cell Motility 1: 237-265, 1981
10. Albrecht-Buehler, G. Is Cytoplasm Intelligent too? In: Muscle and Cell Motility VI (ed. J. Shay) p. 1-21 (1985).
11. Albrecht-Buehler, G. In defense of non-molecular' cell biology. International Review of Cytology 120:191-241 (1990)
12. Albrecht-Buehler, G. The iris diaphragm Model of centriole and basal body formation. Cell Motiltiy and the Cytoskeleton17:187-213 (1990)
13. Albrecht-Buehler, G. Surface extensions of 3T3 cells towards distant infrared sources. J. Cell Biol. (1991)114:493-502
14. Albrecht-Buehler, G. (1992) Speculation about the function and formation of centrioles and basal bodies. In:The Centrosome (ed. V.I. Kalnins) Academic Press, pp 69-102
15. Albrecht-Buehler, G. A rudimentary form of cellular 'vision'(1992) Proc. Natl. Acad. Sci. USA 89:8288-8292
16. Albrecht-Buehler, G. The cellular infrared detector appears to be contained in the centrosome. Cell Motiltiy and the Cytoskeleton 27:262-271 (1994)
17. Albrecht-Buehler, G. Changes of cell behavior by near-infrared signals. Cell Motiltiy and the Cytoskeleton 32:299-304 (1995).
18. Albrecht-Buehler, G., Autofluorescence of live purple bacteria in the near infrared. (1997) Experimental Cell Research 236:43-50
19. Albrecht-Buehler, G. Phagokinetic Track Assay of Cell locomotion in Tissue Culture, In 'Cells: A Laboratory Manual' Vol. 2, Cold Spring Harbor, NY (1997) 77.1-77.10
20. Albrecht-Buehler, G. (1998) Altered drug resistance of microtubules in cells exposed to infrared light pulses:Are Microtubules the 'Nerves' of Cells? Cell Motility and the Cytoskeleton (in press)
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Glossary
(Selected keywords whose explanations I slanted towards the concept of the 'intelligent' cell. They should also be looked up in a standard textbook of cell biology.)
3T3 cells Fibroblasts from a Swiss mouse embryo isolated more than 30 years ago by Howard Green and George Todaro and ever since kept growing in tissue culture as a permanent cell line.
centrioles Centrioles are a pair of small cylinders (0.5 µm x 0.2 µm) oriented perpendicular to each other and located inside the centrosphere adjacent to the nucleus. During mitosis cells place them at the spindle poles. Therefore, only eukaryotic cells may have centrioles. They are found predominantly in animal cells, while most plant cells do not have centrioles. However, both plant and animal cells can make them de novo if they differentiate into migrating cells. For example, human cells have no centrioles during early embryonic development. The fertilized human egg has no centrioles and continues to divide until gastrulation begins and with it the massive migration of cells from the mesoderm. At that point every cell equips itself with a pair of centrioles. Therefore, the frequently copied statement from textbooks that centrioles organize mitotic spindles is wrong: Plant cells and early human cells have perfect mitotic spindles, but no centrioles. We believe that centrioles are the 'eyes' of cells [See ref 9,ref 14,ref 16]
centrosome Discovered and named by early cytologists as an organelle-free spherical area near the nucleus of a cell. It is associated with the Golgi apparatus and contains the pair of centrioles in animal cells. In interphase cells the microtubules radiate unbranchingly from the centrosome to the cell cortex. In dividing cells the centrosome organizes the spindle poles from which the spindle microtubules radiate unbranchingly to the chromosomes. Fertilization requires the passing on of centrioles to the zygote. It is one of the most mysterious parts of the cell. Daniel Mazia considers centrosomes "the bearer of information about the cell morphology". We would like to go further and consider the centrosome as the 'brain' of the cell.
centrosphere(see centrosome)
cortex A dense layer of contractile proteins (actin, myosin, etc.) right underneath the plasma membrane. It executes changes of cell shape and generates the major types of motile surface projections (pseudopodia) such as filopodia, lamellipoia, and blebs.
cytoskeleton A network of 3 types of protein polymers, namely the microtubules, the intermediate filaments and the microfilaments. It also contains numerous proteins that are associated with the fibrous polymers. They nucleate, bundle, cap and link the fibers with each other, with cell organelles and the plasma membrane. It is the mechanical and functional framework for every known cellular function.
cytoplasmic asters The radial array of microtubules of interphase cells with the centrosome at its center. The cytoplasmic asters are distinct from the mitotic asters that radiate from the spindle poles of a dividing cell. In the context of our research we mean specifically radial arrays of microtubules that were regenerated after an anti-microtubular drug had disassembled the original array of microtubules.
emergence The phenomenon that the whole may be more than the sum of its parts ('1+1>2'). For example, flight is an emergent property of all the mechanical parts of an airplane: None of the parts can fly, but the whole of the parts can. Applying this concept to 'intelligence' one may claim that intelligence is an emergent property: ....the level of cell intelligence emerges from the intelligence of cell compartments.The level of organism intelligence emerges from intelligent cells. The level of intelligence displayed by entire populations emerges from intelligent organisms. The level of intelligence of an ecology emerges from the intelligence of its populations... and so forth.
fractal The structural property of an object that consists of self-similar parts. In other words, the parts are smaller copies of the object. So are the parts of the parts, and so forth ad infinitum.
intermediate filaments One of the 3 cytoskeletal fiber types. They have a diameter of 10 nm and are composed of a large family of proteins. A subset of intermediate filaments are also known a keratin fibers which give skin and hair their mechanical strength.
lysosomes Organelles that contain lytic enzymes. They represent the 'digestive' system of cells.
microplast Microplasts are fragments of cells that remain alive for many hours.They come in various sizes. The smallest contain about 2% of a cell volume and consist mostly of cortex surrounded by a plasma membrane. Their movements are autonomous, but restricted to the universally observed shape changes such as spreading, attaching, ruffling, blebbing, waving of filopodia etc. Unlike whole cells they cannot move their entire body to another location after they were forced to round up and respread. This procedure destroys all directional properties that might have been left in their bodies from their parental cell. Microplasts cannot restore or create directionality of movement.
microtubules One of the 3 cytoskeletal fibers. They have a diameter of 24 nm and appear to be hollow tubes, although there are cases where they are filled with an unknown substance.They are composed of two proteins and appear prominently in mitotic spindles. In interphase, they form cytoplasmic asters. The blades of centrioles are composed of microtubules. Our research suggests that they are the 'nerves' of the cells.
mitochondria The 'power supplies' of cells. I believe, they also represent pulsating near infrared light sources because they contain the vast majority of porphyrin (heme-)containing proteins in tissue cells, namely the cytochromes. In phase contrast microscopy they appear as squiggly lines. They 'swim' in a snake-like fashion autonomously through the cytoplasm. They divide autonomously because they are the only cellular compartment with its own DNA. However, that DNA is not a complete genome. Another part of their genome, however, is contained in the cell's nucleus requiring a remarkable level of co-operation between the two.
nucleus From the point of view of the 'intelligent cell' the nucleus is the main library. It contains the blueprints and instructions that have evolved over one billion years of evolution, which tell the cell how to operate, how to rebuild itself (including its 'nerves' and 'brain') after every cell division, and how to act and interact with other cells as they build and maintain an organism. Topologically speaking, the nucleus is located outside the cell because there is a closed surface between it and the cytoplasm. This surface is not entirely closed, though, because it is pierced by so-called nuclear pore complexes.
But there is more. Its gene control systems handles huge numbers of signals that arise from within the nucleus and from its outside word, the cytoplasm. It seems to be structured as a hierarchy of levels of genomic instructions. Starting with genes which constitute the most basic level, transposons may belong to a meta-level in the sense that they represent instructions for genes. There may be a meta-meta-level of 'itinerons' that determine the destinations of transposons, and so forth.
In short, the nucleus, far from being a 'dumb' library of the intelligent cell, is clearly an intelligent system in its own rights. We may be seeing here the first glimpse that intelligence is a fractal property: Intelligent ecologies contain intelligent populations,which contain intelligent organisms, which contain intelligent cells, which contain intelligent compartments, which contain...and so forth.
plasma membrane The 'skin' of the cell that transmits materials and sensory signals beween the inside of the cell and its outside world.
phagokinetic tracks A biological 'cloud chamber' that allows cells to record their own movements in the form of tracks that they leave in a carpet of tiny gold particles on the substrate. [See examples and ref 1, ref 2, ref 4 ]
pseudopodium A motile and ephemeral surface projection out of the cortex of a cell. Examples are filopodia, lamellipodia and blebs.
ruffle A lamellipodium in the process of folding back onto the cell body from which it extended earlier. Seen from the side, ruffles are straight like pencils that swivel around one end near the substrate.
tail The rear part of a migrating cell which usually has a pointed shape that retracts to the body every so often during locomotion [See example]. Both front and tail of a migrating cell are expressions of its so-called polarity. Polarity, in turn, is the expression of the remarkable ability of a cell to turn its initially undirectional body into a directional (vectorial) shape in and out of itself. Mathematicians would call this turning of a scalar into a vector a violation of the Curie principle which is presumably another hint that cells have information-processing abilities.
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Discussion forum
Scientific Press
Comments by the scientific press
- June 1977 Cover of Cell
- September 1977 Scientific American p102-105, Science and the Citizen: Gold Dust Twins
- January 17, 1979 Newsday Part II/1,3 On the Trail Of Moving Cells
- August 20, 1979 Newsweek p 48,52 In: Secrets of the Human Cell
- January 1981 Hospital Practice 16 p28-37 Are Cancer Cells 'Fittest' in Darwinian Struggle?
- March 1981 Scientific American p 86, Science and the Citizen: The Moving Finger
- July/August 1981 Mosaic p 21-27 The Mystery of Cell Movement
- 1983 Introduction of Molecular Biology of the Cell (1st Edition) (ed. B.Alberts, D.Bray, J.Lewis, M.Raff, K.Roberts and J.D.Watson) p XXXIII-XXXVIII, Garland Publishing, Inc. New York .
- 1990 Cover of Cell Motility and the Cytoskeleton Vol 17/4.
- August 1991 Nature:352 p 665, News and Views: Seeing red.
- November 7, 1992 NewScientist p 14 Cells Open Their 'Eyes' To Infrared
- June 1993 Discover p 64 Cells That Reach Out For the Light
- 1996 Life Itself by Boyce Rensberger (Oxford University Press) p. 56-60
Invited articles in monographs
- (1976) Cell Motility (ed. R.D.Goldman, T.Pollard, J.Rosenbaum) Spring Harbor Conferences on Cell Proliferation III, Cold Spring Harbor, NY
- April 1978 Scientific American [See ref 4]
- (1979) The role of intercellular signals: Navigation, Encounter, Outcome. (ed. J. Nicholls) Life Science Research Report 14: 75-96, Verlag Chemie Berlin
- (1982) Natl. Cancer Inst. Monogr. 60, International Symposium on Aging and Cancer (Org. Senator Claude Pepper, Lewis Thomas)
- (1982) Cold Spring Harbor Symposia on Quantitative Biol XLVI, Cold Spring Harbor, NY
- (1984) Cancer Cell 1 (ed. A. Levine, W. Topp, J.D.Watson), Cold Spring Harbor, NY
- (1985) Experimental Biology and Medicine 10, Karger, Basel
- (1985) Muscle and Cell Motility VI (ed. J. Shay), Plenum Press New York
- (1988)Biotechnology and Bioapplications of Colloidal Gold(ed. R. Albrecht, G.M. Hodges), Scanning Microscopy International, Chicago
- (1990) International Review of Cytology Volume 120, Academic Press, San Diego, New York
- (1992) The Centrosome (ed. V.I. Kalnins) Academic Press, San Diego, New York
- (1997) 'Cells: A Laboratory Manual' Cold Spring Harbor, NY
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Acknowledgement
Over the years I have been continuously supported by various funding agencies. The work presented in Chapter 2 has been supported by grants from the National Institute of Health and the National Science Foundation. The work presented in Chapter 3 has been supported by grants from the Office of Naval Research, the United States Army Research Office and the Airforce Office of Scientific Research.
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