exchemist
Valued Senior Member
None of which has anything to do with this thread, which is asking about differences between neurons in various eukaryote organisms.
Oh and BINGO! of course.
Neurons: humans v. pigs, ants and worms...
- Thread starter Speakpigeon
- Start date
Oh and BINGO! of course.
Write4U
Valued Senior Member
And in response I post what different eukaryotic organisms fundamentally have in common, which I believe to be vastly more informative than listing an infinite number of differences. At least one (1) difference for every single individual of every species.
But all living organisms require and have in common biochemicals, that is fundamental. Next comes the processes of biochemical interactions and patterns. Here is where the microtubules dwell, directly above the elementals, and are responsible for the processes necessary for dynamic development of organisms themselves.
But where they all do have microtubules in common, variegation (differences) happens almost immediately from nanoscale patterns for adaption to any specific environment.
I'm sure an extremophile is fundamentally already very different from most other organisms.
Thank you, I like Eureka better, but BINGO will do.
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exchemist
Valued Senior Member
So, in short, you are once again attempting to hijack somebody's thread to talk about your obsessions.
Yazata
Valued Senior Member
That particular chapter, yes. The preceding chapters discussed the genes that mobilize undifferentiated stem cells into becoming neurons, along with the evolution of the elaborate array of proteins that facilitate the transmission of electrochemical signals across synapses. And since it's a book about evolution, it discusses these things in a comparative phylogenetic context. So I was suggesting that Speakpigeon might find the answer he's seeking there.
Is there a whole lot of computation within neurons? I'm more inclined to see them as something like switches, like gates in computer architecture.
It's a beautiful microphotograph and impressive in that technical respect.
Nobody doubts that microtubules are important parts of most eukaryotic cells. So are cell membranes and all kind of other things. None of them are the secret of life all by themselves. Rather, life emerges from how they all work together, in concert.
Maybe you need to start a new thread (don't hijack Speakpigeon's) and try to explain why you believe that microtubules "do the computational work" and should be considered "the seat of conscious sentience". Try to provide some justification for that belief. Frankly, I perceive these ideas as being rather crankish.
I fail to see the relevance. A paper about a cancer drug's effects on microtubules doesn't seem to have anything to do with their supposed role as data-processors or their supposed role as the seat of consciousness.
I'm not convinced that's what Alzheimer's is due to. But supposing for the sake of argument that you are right, we still have the problem of relevance. If microtubules are important in the life of neurons, if neurons (behaving collectively and en-masse) are responsible for neural data processing, memory and cognition, and if Alzheimer's messes up microtubules (hence killing neurons), then we have an account of how Alzheimers degrades mental functioning, but still haven't established what you seem to want to establish, that microtubules are the seat of consciousness.
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Write4U
Valued Senior Member
Are meiosis and mitosis (cell division) a computation? Seems very much like a mathematical copying of an original cell.
Without cell division there can be no life of any kind, complex or simple.
Doesn't that question warrant research?
AFAIK, microtubules are multi-tasking computers (processors) and there are a lot of them.
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Write4U
Valued Senior Member
Question is what coordinates all these functions. It is the MTOC or Microtubule Organizing Center.
I believe it begins by building a cellular cytoskeleton. In a computer that would be the hardware distributed throughout the entire cell structure of the organism.
https://en.wikipedia.org/wiki/Cytoskeleton
Actin filaments are shown in red, and microtubules composed of beta tubulin are in green.
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exchemist
Valued Senior Member
.......and the hijacking continues. This is completely off-topic for this thread, which is about differences between neurons in animals.
Write4U
Valued Senior Member
There isn't any in mammals (same progenitor) and very probably in all biological neural systems. Fundamentally all Eukaryotic organisms have microtubules in common, which are all very simple and of similar configuration. They seem to function quite adequately in all organisms that employ them.
https://en.wikipedia.org/wiki/List_of_animals_by_number_of_neurons
Quora.
https://en.wikipedia.org/wiki/List_of_animals_by_number_of_neurons
There seems to be a strong correlation between number of neurons and ability to function successfully in nature. Evolution seems to work just fine.....
You're the chemist, where do you want to go with this?
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exchemist
Valued Senior Member
I will make no further responses to you on this thread as I do not wish to help you hijack it.
Write4U
Valued Senior Member
So you don't want to get it back on track? I have no intention of hijacking anything. I am responding to the OP question and spent a considerable amount of time doing the research.
Ok, sounds to me you have no idea how to approach that question. Fine by me. I won't accuse you of ignorance, but I do believe you are merely obstructing what might be an interesting discussion on neurons and how they function.
Any difference would reveal themselves during an in-depth discussion. Something you don't seem interested in. Right?
Write4U
Valued Senior Member
That's why I specified that microtubules do (simple) computing.
When you see the proteins travel along the scaffolding, that is the observable part of the computing function. The Motor proteins and the Tau proteins perform instantaneous calculus where to send information. Very much like a chemically based computer.
The messengers are named "qubits". Here it seems we combine chemical with electrical bahaviors. This may explain further.
And to complete this segment;
I see not much difference between chemical information and electrical information. Both are processed as "bits", discreet packets of causal information. Computation is required to translate the inherent values of the qubits
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Bells
Staff member
Mod Note
Such as this one.
If you wish to discuss microtubules, please start a thread about it and go hard at it to your hearts content..
Here is this thread's opening post:
So, while we all really appreciate yet another lecture about microtubules, it really is not necessary and you have taken over the thread with it. Please stop.
Because there are pages of posts across this board where you go on about it repeatedly (a search for name and microtubules came back with 7 pages in the last year), even in topics that have nothing to do with it.
Such as this one.
If you wish to discuss microtubules, please start a thread about it and go hard at it to your hearts content..
Here is this thread's opening post:
I have emphasised the important part..
So, while we all really appreciate yet another lecture about microtubules, it really is not necessary and you have taken over the thread with it. Please stop.
Write4U
Valued Senior Member
Do discussions about neurons such as this one warrant 7 pages of pertinent information?
Yes, we are talking about neural functions. Can you offer an example of a functional difference between neurons of a human and the neurons of other species, such as pigs, a close relative other than a difference in the function of their microtubules?
I have addressed the OP question and much more. But I am getting the feeling this is like offering pearls before the "pigs".
No, apparently you do not really appreciate another lecture about microtubules. You are even advocating that less knowledge on this subject is better. I disagree.
Especially on a topic as important as microtubules, a common denominator in all Eukatyotic organisms, which fill several diverse functions inside neurons, including photo-synthesis.
Hey, that function hasn't been mentioned yet. I wonder why? Lack of information?
IMO, any discussion of neurons should involve the functions of microtubules.
No one would discuss sight without mentioning eyes. Or hearing with out ears.
No one would discuss religion without mentioning God.
There are no neurons without microtubules. Any discussion of neural function can only be addressed via microtubules. They are the functional part of neurons.
I am anxiously looking forward to any post about neurons. Except for a a few pertinent facts, all I have seen so far is bickering about semantics as usual. Nothing that taught me anything anyway.
Ok I'll honor your request, albeit under protest. This will be my last post on this topic.
Again I extend an invitation to all to please post something so that I am no longer hijacking this thread. Without other postings the last poster has hijacked the thread? Well, let's see where we end up.
Have at it.
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Bells
Staff member
I don't know, do you think it was pertinent to explain microtubules in a thread about abortion?
That was a rhetorical question..
If I was advocating for less knowledge and understanding, I would not have recommended that you start a thread about the subject.
I'm just saying that what you are doing is not pertinent to this particular discussion.
I'll give you an example. A friend of mine is a somewhat a fan of Elon Musk. Every discussion about cars, technology, space, planets, science, computers, technological development, cave diving, solar panels, the environment, batteries, marijuana, etc.. He brings up Elon Musk. Without fail. Our collective groan of dismay is not because we do not wish to learn about Elon Musk or extol his virtues. It's just that not everything has to be about Elon Musk. He does not have to be present in regards to every subject matter.
The same can be said for microfilaments and neurofilaments. Something something about a time and place applies here.
Protest is noted.
And thank you!
Very interesting! I have never heard of microtubules. Interesting how microtubules can give intelligence to an organism with or without neurons. I am not sure if you are still discussing the topic or if microtubules is an off topic discussion in this thread but I thought I would reply to you. Are microtubules hard science or pseudoscience?
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Write4U
Valued Senior Member
If you like to read more on this, I started a topic awhile ago. It has more links and in-depth discussion about microtubules.
See: Is consciousness to be found in quantum processes in microtubules (Biology & Genetics)
Speakpigeon
Valued Senior Member
OK, I've skimmed through Hercules Rockefeller's links and found that most specialists seem to lean somewhat in favour of a broad similarity between neurons across the vertebrate-invertebrate division line.
However, there doesn't seem to be anything like a scientific position on this yet. Further, neurons have evolved and there may be different points along this long evolution where neural-like cells have acquired the various structural characteristics that give our neurons their functional value. Thus, there is no doubt that at least some species must have, or must have had, neural cells with some functional differences compared to our own neurons.
There are also suggestions that the main difference is the number of neurons and the organisation of these neurons into a functional whole rather than functional differences between the neurons themselves, with the suggestion that the same neuron is probably capable of functionally different roles depending on where it happens to be located within the whole system of neurons, and therefore what connections it has with other neurons.
I put a selection of what I found that give some light on the subject. None of these people provide anything like a direct answer to my question, but there is definitely a broad direction of travel, at least for now.
To think about this problem, we can think of limbs and how different species incarnate the different solutions to the problem of using extensions to the body to perform some activities on behalf of the organism as a whole. Although these solutions can be structurally very different from one species to the next, the functionality can be remarkably similar.
It should be noted that the brain has local areas which themselves have functionally different roles, for example memory, perception or language. Yet, the neurons are probably essentially of the same model across the brain, each neuron only developing in situ a specific set of characteristics according to the area where it is located.
See in particular the last paragraph.
In any case, there seems to be still an awful lot to be discovered about our neurons although it is probably going much faster today.
EB
Vertebrate versus invertebrate neural circuits
https://www.sciencedirect.com/science/article/pii/S0960982213006349
Eve Marder
Brandeis University, Waltham, USA
Many years ago, invertebrate circuits were often called ‘simple”. Today we know that small circuits are quite complex and show dynamics that reveal many fundamental principles of circuit function. These principles provide a library of circuit mechanisms that are almost certainly used in all large brains. Indeed, any mechanism found first in small nervous systems (for example, bursting neurons, widespread neuromodulation, electrical coupling) eventually has been revealed in larger brains. To me, the essential question is how special features arise in large networks precisely because of their size, despite the fact that many explanations of how large circuits work resort to describing them as if they were small circuits.
Sten Grillner
Karolinska Institute, Stockholm, Sweden
The general features of the control systems for motion (sensory and network level) are similar in invertebrates and vertebrates. Moreover, recent evidence suggests that more advanced invertebrates (protostomes) and vertebrates have a common design of forebrain circuits. At the microcircuit level, a variety of invertebrate systems have contributed importantly, notably the stomatogastric system. Vertebrate circuits tend to be more complex with larger numbers of interacting nerve cells. On the other hand, vertebrate cells are simpler to analyze, since the cell body is located between the dendrites and the axonal spike initiating zone. In contrast, invertebrate neurons have their processes located in a dense neuropil in the central parts of the ganglia, and signals from dendrites and axons are transmitted passively to the unipolar cell body.
Alexander Borst
Max-Planck-Institute of Neurobiology, Martinsried, Germany
Clear structural similarities exist in peripheral processing stages of vertebrate and invertebrate nervous systems — for example, between the nicely layered optic lobe of insects and the vertebrate retina, or the glomerular organization of the insect antennal lobe and the olfactory bulb of vertebrates. These similarities apply to functions as well. Telling examples are the convergence of spatially distributed olfactory receptors with the same odor response spectrum in single glomeruli in the olfactory system or the splitting of photoreceptor input into parallel ON- and OFF-processing channels in the early visual system of both animal groups. To what extent the actual circuits performing a particular computation are similar remains to be seen. Given the current intense investigations in both the retina and the fly optic lobe, the circuit for local motion detection might be the first case where this question can soon be answered.
Ralph Greenspan
Kavli Institute for Brain and Mind, San Diego, USA
They are likely transferable in several respects: first, the functional and computational strategies in invertebrates, where they are more easily discernible, are likely to be found in vertebrates; second, the embryonic gene expression patterns designating brain structures and substructures show a high level of conservation; and third, there is emerging evidence that adult brain structures sharing embryonic gene expression patterns carry out similar tasks and use the same intercellular signaling systems. Examples of the latter are the correspondence between the insect pars intercerebralis and the hypothalamus, and between the insect central complex and the basal ganglia, despite the lack of any anatomical similarities.
William Kristan
University of California, San Diego, USA
The brains of many animals differ in their details: ionic channels, neurotransmitters, neuronal interconnections vary, even between rats and mice. General functional principles, however, are overwhelmingly similar: central pattern generators, lateral inhibition, gain control, balanced excitation and inhibition; the list of generalities across phyla is both extensive and will expand as more circuits are investigated. Finding the mechanisms underlying these principles is more tractable — and more convincing — using a nervous system that is simple enough to be able to both record the activity of many of its neurons during behavior and modify that behavior by stimulating single neurons. Yes, I want to know how human brain circuits work; that’s why I study the leech nervous system!
Dmitri “Mitya” Chklovskii
Janelia Farm Research Campus, HHMI, Virginia, USA
Because both vertebrates and invertebrates often live in the same environment and have similar behavior objectives, the functional requirements on their neural circuits are similar. For example, the statistics of natural visual scenes are reflected in the properties of receptive fields of neurons in the early visual systems: spatial receptive fields are center-surround and temporal receptive fields are biphasic as predicted by efficient coding/predictive coding theories. However, similar functional properties may be achieved by different mechanisms. It would be very interesting to see, by combining connectomes with the results of genetic, physiological, and behavioral experiments, how similar these mechanisms actually are. Both similarities and differences will inform our theoretical understanding of brain function.
https://www.nap.edu/read/13462/chapter/3#4
Surprisingly, the genome of the Poriferan demosponge, Amphimedon queenslandica, contains an almost complete set of genes homologous to those found in mammalian synapses (Fig. 1.1A), although the organism does not assemble any structure morphologically resembling a synapse (Sakarya et al., 2007; Srivastava et al., 2010).
However, there doesn't seem to be anything like a scientific position on this yet. Further, neurons have evolved and there may be different points along this long evolution where neural-like cells have acquired the various structural characteristics that give our neurons their functional value. Thus, there is no doubt that at least some species must have, or must have had, neural cells with some functional differences compared to our own neurons.
There are also suggestions that the main difference is the number of neurons and the organisation of these neurons into a functional whole rather than functional differences between the neurons themselves, with the suggestion that the same neuron is probably capable of functionally different roles depending on where it happens to be located within the whole system of neurons, and therefore what connections it has with other neurons.
I put a selection of what I found that give some light on the subject. None of these people provide anything like a direct answer to my question, but there is definitely a broad direction of travel, at least for now.
To think about this problem, we can think of limbs and how different species incarnate the different solutions to the problem of using extensions to the body to perform some activities on behalf of the organism as a whole. Although these solutions can be structurally very different from one species to the next, the functionality can be remarkably similar.
It should be noted that the brain has local areas which themselves have functionally different roles, for example memory, perception or language. Yet, the neurons are probably essentially of the same model across the brain, each neuron only developing in situ a specific set of characteristics according to the area where it is located.
See in particular the last paragraph.
In any case, there seems to be still an awful lot to be discovered about our neurons although it is probably going much faster today.
EB
Vertebrate versus invertebrate neural circuits
https://www.sciencedirect.com/science/article/pii/S0960982213006349
Eve Marder
Brandeis University, Waltham, USA
Many years ago, invertebrate circuits were often called ‘simple”. Today we know that small circuits are quite complex and show dynamics that reveal many fundamental principles of circuit function. These principles provide a library of circuit mechanisms that are almost certainly used in all large brains. Indeed, any mechanism found first in small nervous systems (for example, bursting neurons, widespread neuromodulation, electrical coupling) eventually has been revealed in larger brains. To me, the essential question is how special features arise in large networks precisely because of their size, despite the fact that many explanations of how large circuits work resort to describing them as if they were small circuits.
Sten Grillner
Karolinska Institute, Stockholm, Sweden
The general features of the control systems for motion (sensory and network level) are similar in invertebrates and vertebrates. Moreover, recent evidence suggests that more advanced invertebrates (protostomes) and vertebrates have a common design of forebrain circuits. At the microcircuit level, a variety of invertebrate systems have contributed importantly, notably the stomatogastric system. Vertebrate circuits tend to be more complex with larger numbers of interacting nerve cells. On the other hand, vertebrate cells are simpler to analyze, since the cell body is located between the dendrites and the axonal spike initiating zone. In contrast, invertebrate neurons have their processes located in a dense neuropil in the central parts of the ganglia, and signals from dendrites and axons are transmitted passively to the unipolar cell body.
Alexander Borst
Max-Planck-Institute of Neurobiology, Martinsried, Germany
Clear structural similarities exist in peripheral processing stages of vertebrate and invertebrate nervous systems — for example, between the nicely layered optic lobe of insects and the vertebrate retina, or the glomerular organization of the insect antennal lobe and the olfactory bulb of vertebrates. These similarities apply to functions as well. Telling examples are the convergence of spatially distributed olfactory receptors with the same odor response spectrum in single glomeruli in the olfactory system or the splitting of photoreceptor input into parallel ON- and OFF-processing channels in the early visual system of both animal groups. To what extent the actual circuits performing a particular computation are similar remains to be seen. Given the current intense investigations in both the retina and the fly optic lobe, the circuit for local motion detection might be the first case where this question can soon be answered.
Ralph Greenspan
Kavli Institute for Brain and Mind, San Diego, USA
They are likely transferable in several respects: first, the functional and computational strategies in invertebrates, where they are more easily discernible, are likely to be found in vertebrates; second, the embryonic gene expression patterns designating brain structures and substructures show a high level of conservation; and third, there is emerging evidence that adult brain structures sharing embryonic gene expression patterns carry out similar tasks and use the same intercellular signaling systems. Examples of the latter are the correspondence between the insect pars intercerebralis and the hypothalamus, and between the insect central complex and the basal ganglia, despite the lack of any anatomical similarities.
William Kristan
University of California, San Diego, USA
The brains of many animals differ in their details: ionic channels, neurotransmitters, neuronal interconnections vary, even between rats and mice. General functional principles, however, are overwhelmingly similar: central pattern generators, lateral inhibition, gain control, balanced excitation and inhibition; the list of generalities across phyla is both extensive and will expand as more circuits are investigated. Finding the mechanisms underlying these principles is more tractable — and more convincing — using a nervous system that is simple enough to be able to both record the activity of many of its neurons during behavior and modify that behavior by stimulating single neurons. Yes, I want to know how human brain circuits work; that’s why I study the leech nervous system!
Dmitri “Mitya” Chklovskii
Janelia Farm Research Campus, HHMI, Virginia, USA
Because both vertebrates and invertebrates often live in the same environment and have similar behavior objectives, the functional requirements on their neural circuits are similar. For example, the statistics of natural visual scenes are reflected in the properties of receptive fields of neurons in the early visual systems: spatial receptive fields are center-surround and temporal receptive fields are biphasic as predicted by efficient coding/predictive coding theories. However, similar functional properties may be achieved by different mechanisms. It would be very interesting to see, by combining connectomes with the results of genetic, physiological, and behavioral experiments, how similar these mechanisms actually are. Both similarities and differences will inform our theoretical understanding of brain function.
https://www.nap.edu/read/13462/chapter/3#4
Surprisingly, the genome of the Poriferan demosponge, Amphimedon queenslandica, contains an almost complete set of genes homologous to those found in mammalian synapses (Fig. 1.1A), although the organism does not assemble any structure morphologically resembling a synapse (Sakarya et al., 2007; Srivastava et al., 2010).
Thanks for the topic info. If I have time I will check it out.