Do single Cells have 'brains' (sense info proc's) ??

[Widdekind]

In my naive understanding, single Celled organisms swim through their lives, "smelling / tasting" various chemical gradients, and thereby orienting themselves and their movement strategies.

 

• How do single Cells "taste" chemical gradients -- do they use chemo-receptors, on opposite sides of their membranes, to get a "forked-tongue" effect, and "smell in stereo" like snakes ?
  
• If you consider such chemo-receptors as "sense organs", what, inside the cell, is the "sensory data processor" -- to wit, the Cell's "proto-brain", which translates "taste" into movement instructions ??
  
• If, in higher animals, the "seat of cognition" seems associated with the physical brain ("sensory data processor"), is there some similar sense, in single Cells, such that the Cell's "sensory data processor proteins" (if one would allow the broadest of brush strokes) are the "control center" or "HQ" of the Cell ???
  

[Greippi]

When a receptor receives a signal, it initiates a pathway of molecular interactions and chemical reactions that eventually have an effect. There isn't really a "processing unit" the pathway is already in place, and it just follows whatever pathway until its effect.

 

 

A cell is essentially a bag of chemicals that work together.

[granpa]

"cell intelligence" is considered crackpottery

 

no independent thought.

[michel123456]

A cell is essentially a bag of chemicals that work together.

 

Not a gracious definition for the work of Life.

 

Generally speaking, I find that to consider the brain as the only receptacle of cognition is a reductive concept. Surely the brain is the place where information from senses is analyzed, but it looks evident to me that all the work is not made in the brain only. The work must be dissipated everywhere in each part of the body till the last cell. Not that a cell properly "thinks" as we understand it, but that even a single cell must have a basic cognition of its environnement, and a way to transmit this "cognition" to other cells, till it may reach the brain. Maybe this "cognition" is purely chemical in nature, along some "paths" as proposed above, I don't know. But there must be something.

[Widdekind]

When a receptor receives a signal, it initiates a pathway of molecular interactions and chemical reactions that eventually have an effect. There isn't really a "processing unit" the pathway is already in place, and it just follows whatever pathway until its effect.

 

 

A cell is essentially a bag of chemicals that work together.

 

Thanks for your reply.

 

Technically speaking, is not any system, which processes (sensory) information, a "data (info) processing unit" ? That's the limit of my meaning, in this case, I am not suggesting "cell's are smart" (per se)...

 

only that cells (1) have sensors (w/ which they interrogate their environment); (2) process sensor-data (w/ basic, primitive, pre-defined pathways, apparently). Would you not agree, w/ such strict & limited definitions ? (The only "sentience" I am attributing, to single cells, is such limited sensory-information processing, "a limited feeling" for the cell's environment, as it were. Yet, that "small amount of sentience" still separates a "bag full of chemicals working together", from inert physical phenomena, like a clump of chemicals stuck together in a rock, say.) The only question I would further ask is, where does the following analogy break down:

 

eyes (Earth animals) == chemo-receptor (single Cells)

optic nerve pathway == chemical pathway triggered by CR (above)

brain 'sensor-data-processor' == ???

What I'm asking is, at some point, information stops being transmitted & relayed (= "optic nerve"), and begins being processed (= "brain"). Where in a single Cell's chemical pathways, is information processed, and behavioral actions determined / decided ("swim left / right / straight, turn around, etc.").

 

Thanks again for your time to respond.

[Greippi]

 

What I'm asking is, at some point, information stops being transmitted & relayed (= "optic nerve"), and begins being processed (= "brain"). Where in a single Cell's chemical pathways, is information processed, and behavioral actions determined / decided ("swim left / right / straight, turn around, etc.").

 

Thanks again for your time to respond.

 

 

It's all in the pathway. There is no point. Obviously there are "checkpoints" and levels of "control" e.g. relying on concentration gradients or whatever.

 

For example:

 

Sensing something = Molecule A binds to receptor A -> receptor A changes conformation and binds molecule B - molecule B binds molecule C - molecule C binds molecule D -> and so on until FOR EXAMPLE molecule X binds DNA and initiates expression of a gene into a certain protein which has a function.

[granpa]

I wonder if there are any single celled syncytial protists that have parts that correspond to neurons?

 

like c elegans but syncytial

http://en.wikipedia.org/wiki/Caenorhabditis_elegans

 

In addition, C. elegans is one of the simplest organisms with a nervous system. In the hermaphrodite, this comprises 302 neurons whose pattern of connectivity has been completely mapped out, and shown to be a small-world network

Edited December 8, 2010 by granpa

[Widdekind]

It's all in the pathway. There is no point. Obviously there are "checkpoints" and levels of "control" e.g. relying on concentration gradients or whatever.

 

For example:

 

Sensing something = Molecule A binds to receptor A -> receptor A changes conformation and binds molecule B - molecule B binds molecule C - molecule C binds molecule D -> and so on until FOR EXAMPLE molecule X binds DNA and initiates expression of a gene into a certain protein which has a function.

 

What about flagellated single-celled prokaryotes (say) ? If a single-celled prokaryote is subjected to a chemical gradient, so that Chemo-receptors are triggered all over the cell... but mostly in some given direction...

 

then how do all those triggered pathways "compete" and "determine a winner", so that the cell "steers" in that direction ("up" the gradient "hill", towards higher concentrations [or vice versa, if fleeing some sort of toxin, say]) ? Thanks again for your informative responses.

 

I wonder if there are any single celled syncytial protists that have parts that correspond to neurons?

 

like c elegans but syncytial

http://en.wikipedia.org/wiki/Caenorhabditis_elegans

 

Is not "multi-nucleation" a sure sign of multi-cellularity ? What about algae ??

 

Thanks again for everyone's responses !

[granpa]

I really dont understand what you are trying to say.

 

wholly syncytial organisms dont divide their interiors into separate compartments.

its all one cell.

Edited December 10, 2010 by granpa

[Widdekind]

According to Wikipedia:

 

Cellular antennae

 

Within the biological and medical disciplines, recent discoveries have noted that primary cilia in many types of cells within eukaryotes serve as cellular antennae. These cilia play important roles in chemo-sensation. The current scientific understanding of primary cilia organelles views them as "sensory cellular antennae that coordinate a large number of cellular signaling pathways, sometimes coupling the signaling to ciliary motility or alternatively to cell division and differentiation."

 

 

 

 

I really dont understand what you are trying to say.

 

wholly syncytial organisms dont divide their interiors into separate compartments.

its all one cell.

 

I only know of Fungi who do such things, and Fungi are multi-cellular organisms "at root". What were you pondering w/ your post ?

Edited December 10, 2010 by Widdekind

[granpa]

I dont have any one organism in mind.

I do know that ciliates are syncytial

[ewmon]

Interestingly, human brains produce their gray cortical cells deep within the brain (not at the surface), and they make their way (like crawling amoebas) through the existing white brain cells to the brain's surface by following the gradient of a chemical signal produced there. So everyone here discussing this topic has billions of these cells that, at the beginning of their lives, swam around, smelling/tasting various chemical gradients, and orienting themselves and their movement strategies (to paraphrase the OP's words). These are, in fact, the brain cells that are remembering facts, perceiving and comparing information, making judgments, and discussing this topic!

[granpa]

youtube Search results for EUPLOTES CILIADO CILIATE Edited February 3, 2011 by granpa

[granpa]

http://news.sciencemag.org/sciencenow/2011/11/scienceshot-amoeba-sized-insect.html?ref=hp

 

the fairy wasp (Megaphragma mymaripenne) compared to a paramecium and amoeba

 

Edited November 19, 2011 by granpa

[ewmon]

In my naive understanding, single Celled organisms swim through their lives, "smelling / tasting" various chemical gradients.

Interestingly, in the developing brain, cortical cells sense chemical gradients and crawl relatively great distances to find their proper location.

[granpa]

Edited November 21, 2011 by granpa

[Greg Boyles]

I suspect what the original poster is attempting to argue here is that single cells are conscious or that single neurones have a proportion of the total conscious of a whole brain.

 

Haven't we been through this before.

 

All the evidence thus far is that single cells, protists or neurones, are not conscious or self aware.

 

 

In your computer, does a single transister in your CPU possess 0.000x% of the functionality of Windows XP that you are interpreting on the screen?

 

Answer - definitively no!

 

A transistor simply sits there at lets current flow through it or not.

 

It does not know whether it is helping to run Windows XP or Linux.

 

It knows nothing of what is happening on the screen or how the user of the program running on the whole computer is interpreting it or interacting with it.

 

If there was no video adapter in the PC and no screen, then we would not be able to interpret anything running on the PC. It would be just a bunch of meanlingless currents running and that we might be able to measure individually with a multimetre.

 

Currents in individual transistors -> Windows XP is ermegent complexity made possible by the existence of a video adapter, a screen and of course our brains.

 

The relationship between individual neurones in our brain, our whole brains and our consciousness/self awareness is similar to the relationships between individual transistors, the CPU, the whole PC and Windows XP.

[CharonY]

The important bit is that single-cell signal processing is very limited as opposed to multi-cellular signal processing. Due to physical limitations there is far less plasticity in the regulatory networks. Sure, one could use similar words (like sensors) but the scope and potentials are vastly different. In the end, it is basically a scaling issue.

[granpa]

I suspect what the original poster is attempting to argue here is that single cells are conscious or that single neurones have a proportion of the total conscious of a whole brain.

 

Haven't we been through this before.

 

All the evidence thus far is that single cells, protists or neurones, are not conscious or self aware.

 

 

In your computer, does a single transister in your CPU possess 0.000x% of the functionality of Windows XP that you are interpreting on the screen?

 

Answer - definitively no!

 

A transistor simply sits there at lets current flow through it or not.

 

It does not know whether it is helping to run Windows XP or Linux.

 

It knows nothing of what is happening on the screen or how the user of the program running on the whole computer is interpreting it or interacting with it.

 

If there was no video adapter in the PC and no screen, then we would not be able to interpret anything running on the PC. It would be just a bunch of meanlingless currents running and that we might be able to measure individually with a multimetre.

 

Currents in individual transistors -> Windows XP is ermegent complexity made possible by the existence of a video adapter, a screen and of course our brains.

 

The relationship between individual neurones in our brain, our whole brains and our consciousness/self awareness is similar to the relationships between individual transistors, the CPU, the whole PC and Windows XP.

 

all I can say is that this is one impressive transistor

 

[Mr Skeptic]

In my naive understanding, single Celled organisms swim through their lives, "smelling / tasting" various chemical gradients, and thereby orienting themselves and their movement strategies.

 

• How do single Cells "taste" chemical gradients -- do they use chemo-receptors, on opposite sides of their membranes, to get a "forked-tongue" effect, and "smell in stereo" like snakes ?

They use cell surface receptors, which set off a chemical signal cascade when they detect something. It's not really stereo, since there are far more than two receptors. It could in theory have a lot of data, but it is communicated largely via a chemical gradient due to the speed of diffusion.

 

 

 

• If you consider such chemo-receptors as "sense organs", what, inside the cell, is the "sensory data processor" -- to wit, the Cell's "proto-brain", which translates "taste" into movement instructions ??

Ultimately, it is the DNA and the proteins which read it that are the brain behind everything happening in the cell. However, in many cases the setup from sensing to movement, was set up to occur automatically, before any sensing happened.

 

 

 

• If, in higher animals, the "seat of cognition" seems associated with the physical brain ("sensory data processor"), is there some similar sense, in single Cells, such that the Cell's "sensory data processor proteins" (if one would allow the broadest of brush strokes) are the "control center" or "HQ" of the Cell ???

 

Not unless you consider the arrangement of receptors, internal receptors, and motor proteins to be the seat of cognition.

[granpa]

if there is a control center in a cell then neurons should be packed full of it since that is their only job

 

theres not much in axons and dendrites except microtubules.

 

the body of teh neuron isnt much bigger than the nucleus itself.

 

http://www.physicsforums.com/showthread.php?t=257289

http://www.physicsforums.com/showthread.php?p=1897203#post1897203

http://www.physicsforums.com/showthread.php?p=1897408#post1897408

 

something else to consider, that many people dont know, is that

the cell can continue to fire 100,000's of times after the ion pumps that 'recharge' the cell have stopped working.

Edited November 22, 2011 by granpa

[Mr Skeptic]

if there is a control center in a cell then neurons should be packed full of it

 

Why? Neurons have a complicated cell shape that is largely responsible for what they do. If much of their function is due from that, why would they also need to be "packed full of" some other control center?

 

If anything impresses me about cell-level intelligence, it would be our immune system.

[Greg Boyles]

all I can say is that this is one impressive transistor

 

 

 

If you are refering to the 'cuddling', then how the f can you possibly prove that these protists are really cuddling as humans do.

 

It could be anything, just trying to get past each other, some form of sexual reproduction that necessitates close contact,............

 

You can't interpret the behaviour of non-human organisms through the lens of humanity - it is just idiotic.

[granpa]

Dude. I didnt name the video

[CharonY]

More complex immune system as ours requires cell populations to interact. Moreover, the DNA is clearly not a central control center. In fact, nothing like this exists in a cell. Regulation is fairly distributed and occurs on basically all levels. The DNA is, alone, probably the most inert stuff within the cell. All the information is maintained and acted upon primarily by proteins in conjunction with metabolites and the DNA itself (to put it very simply and horribly inaccurate).