Neurogensis

misskitty

Does anyone know what neurogensis is? How is it related to human memory function?

~Kitty

Mattara

Hello,

The best way of learning new term is to go to www.google.com, type Define:yourword.

http://www.google.se/search?hl=sv&q=...ogenesis&meta=

After that you could try just typing the word itself.

http://www.google.se/search?hl=sv&q=...S%C3%B6k&meta=

I tell you this because neurogensis (the production of new nervous tissue) is a rather complex (and rather new) subject and requires a lot to write to make it clear to the reader.

Taoist

Memory and neurogenesis is a little different. Memories are held by fixed glial cells, see axiom (myelin sheath) for an idea how glial function for set responses as a function and neurogenesis is more of the routes taken and the growth thereof.

The brain as a topic was my first paper but I will not go to far without direct questions and I can point you to information to reach a conclusion.

For neurogenesis itself try single cell application look at how tubules within a cell acts almost like the central nervous system to a single cell.

No…… this pursuit is not new... http://www.sdbonline.org/fly/aimorph/maltubls.htm#dafka

What is neat is how the information is conveyed; note the width (nm) of the tubules and then the molecular structures themselves … there is a key within this….

DocToxyn

Most likely this thread will get moved over to the mind and brain sciences section and there you can find some more info on neurogenesis. I also recently did a review of an article on adult neurogenesis and memory function in that section. In that I provided some introductory material that may help you out.

In short, the term can be defined as the creation of nerve cells. This occurs primarily during development in the womb, but also some in early postnatal life and it continues in specific regions of the brain throughout adult life. As far as how it relates to memory, it's still a topic of investigation but neurogenesis does occur in regions of the brain that are also associated with memory and learning, ie the hippocampus. There are other processes/phenomena such as synaptic plasticity, budding that probably also play a role in memory function in the brain.

DocToxyn

Do you mean "axon"? If so this structure of the neuron is associated with myelin-based structures, but those come from other cells, ie schwann cells in the periphery and oligodendrocytes in the central nervous system and are these are not neuronal cells. Do you have any references for the "memories are held by fixed glial cells" statement?

Moonbear

What does that site you linked to have to do with neurogenesis?

I'm going to back up DocToxyn here and ask that you provide a reference for your statement that memories are held in fixed glial cells, as that sounds a bit off-the-wall to me!

As DocToxyn already explained well, neurogenesis is a term referring to the formation of new neural cells. Learning and memory are an area of research where it is hypothesized neurogenesis plays an important role in adults, so you can find published studies that discuss neurogenesis pertaining to that field of research, but that is not part of the definition of neurogenesis, but rather a probable function of the neurogenesis that continues in adulthood.

Taoist

Neurogenesis is not new. That site showed that neurogenesis has been around while.

Neurogenesis and memories is where I was communicating and the Doc may understand what he feels is correct. Or of a hypothesis and all I did was share an example of where Glial function in a reoccurring or memory event. Just because it does not recall an event in time like in psychology, the same function of reigniting ‘its’ same event is in myelin sheath or as some call it muscle memory.

What was the Glial count of Einstein’s brain mass? Take a look.

Memories can continue to develop, neurons don’t as a general rule, neurons wire up the system and hold the base memories until sleep, that is when we use our energy to hard wire the memories within our Glial, please run through the research, I have no reason to bs. My first work at age 15 was on the brain in 82’, please don’t play games let’s articulate and we may both learn a bit, I am never to proud to learn.

I would love to have you show me how it works.

Moonbear

That site showed nothing of neurogenesis. And, of course neurogenesis is not new. Nobody said it was. However, the discovery of neurogenesis in adult humans is fairly new.

It is not what we "feel" is correct, it is what the scientific literature demonstrates. You did not share an example, you shared a guess. Show us evidence backing up your statement if you want us to believe it's more than a guess.

Nobody would know, because nobody examined that.

Okay, your book report at 15 is not neuroscience; DocToxyn and I are both neuroscientists by profession, as are a few others on this board, and we are not playing games. Indeed, we ARE trying to help educate you on this. A good deal more has been learned about neurogenesis since 1982. Neurons in the areas of the brain implicated in learning and memory, such as the hippocampus that DocToxyn mentioned above, do indeed continue to generate.

Why don't you try reading the thread DocToxyn recommended to you first. It's as good of a starting place as any, and we'd be happy to help teach you, but we cannot teach you everything on an internet forum...it would take years of formal study just to get the basics of the field.

DocToxyn

Glia have indeed come a long way since they were first thought to be the "glue" holding the nervous sytem together. I can't argue that glial cells don't have a role in memory and learning, in fact I found several references in peer-reviewed journals that describe the ever increasing interconnection between neurons and glia. Glia-neuron interacitons in nervous system function and development and Glial cells in synaptic plasticity are both recent articles that delve into the modulation and mediation of synaptic plasticity by glia and how this may relate to memory.

Exactly how they do this is still under investigation. That said, I'm still having trouble with your statement about "hard wiring memories into glia", can you elaborate. I'm not sure if this is me just not being able to understand you posts or that you're confused regarding the literature you have read, maybe both... Can you help me out...what's your backgound in neuroscience, is english your first language? I'm not trying to berate or interrogate you, just trying to get a feel where you're coming from.

Taoist

For the moonB


The brain of Albert Einstein has often been a subject of research and speculation. Einstein's brain was removed within 7 hours of the death of the famous physicist

Einstein's brain also contained 73 percent more glial cells than the average brain

http://en.wikipedia.org/wiki/Albert_Einstein's_brain

Hello Doc, thanks for at least looking at my comment. Glial are fixed upon having a duty offering a refractive property. The molecular make up will assist in this.

Moonbear

After looking into it further, it turns out you are correct on this. I had never heard about this before. However, your interpretations and information are still highly flawed.

Wikipedia is not a reliable source of information. There is no factual basis for that claim. The only study that measured the glial content in Einstein's brain only examined 4 areas - areas 9 and 39 from the right and left hemisphere. http://www.ncbi.nlm.nih.gov/entrez/q...&dopt=Abstract
Diamond MC, Scheibel AB, Murphy GM Jr, Harvey T. On the brain of a scientist: Albert Einstein. Exp Neurol. 1985 Apr;88(1):198-204. And, the analysis was only done on a SINGLE 6 or 20 micron section from each area!

However, there were MAJOR flaws to this study and the conclusions drawn from it. First, the "controls" were not age-matched. There are differences in neural and glial composition of the brain with aging. Second, and more importantly, the study reports ONE of those 4 areas as having a statistically significant different "ratio" of glial to neuronal cells, yet, anyone with even a basic course in statistics knows you cannot do a statistical test when your "experimental group" consists of only ONE subject. Even worse, given the number of comparisons they did (their statistical approach was atrocious!...it was clearly a fishing expedition), they did not apply Bonferroni's corrections to those statistics (however they managed to arrive at them), which means even what they called significant is not. It's especially interesting that they find a significant ratio without finding a significant difference in absolute cell counts, which suggests there was truly no difference until they started playing with the numbers.

For the detailed discussion of the flaws, see this later article:
Hines T. Further on Einstein's brain. Exp Neurol. 1998 Apr;150(2):343-4.

http://www.ncbi.nlm.nih.gov/entrez/q...&dopt=Abstract

The original study and its flaws are also presented here in less technical terms:
http://staff.washington.edu/chudler/ein.html

Also noteworthy is that Einstein's brain was stored in formalin for several months, then embedded in celluloidin and stored in alcohol until the time of study. Formalin is a very harsh way to store brain tissue, and neuronal morphology is severely compromised in such tissue (I know this from first-hand experience working with post-mortem brain tissue preserved in that manner), which would also compromise the ability to accurately count neuronal density after such a long period of preservation (the best preservation of morphology in animal tissues is obtained with less than a 24 hour period of fixation after perfusion, and subsequent storage in the freezer in a cryoprotectant solution). Celluloidin embedding and storage in alcohol also leads to a substantial shrinkage of the tissue, introduction of embedding artifacts, and dehydration. The decades of storage alone could lead to quite substantial differences from more recently collected tissues.

Again, as far as I can tell here, you're just stringing together words in a way that has no meaning. What do you mean by a "refractive property?" You have yet to provide any support for these types of claims.

Taoist

Hey thanks for the depth and clarification regarding Einstein’s brain.

As for resources well I use everything and I googled up Einstein’s brain to see if that info was readily available for you but I feel you spent much more time to make your point.

Before we can tackle the Glial question can we agree on this below, first? Just too make sure I am not working from bad information. I wrote this up just for you since you cared enough to help me with the big ‘E.’

Glial cells are the most numerous cells found in the brain. There are 2 familiar types’ astrocytes and oligodendrocytes of the macroglia variety. A type of Glial or microglia derived from the monocytes which grow in bone marrow can be specialized macrophages. These types are found throughout the body fluids. Glial appear similar to neuron with dendrites but they have a few distinct differences; they do not generate action potential or release neurotransmitters yet maintain the ability of mitosis unlike neurons. In a mature state they are fixed to a specific site and lose this mitosis state. They are heavy with the alkali metals such as K, Na and C.

Astrocytes are the largest of the Glial numbering approximately 10 to 1 of the neuron cell count. They are star shaped when free but will adhere to neurons as to repair or stabilize a neuron and become a support addition with a variety of shapes. Glial can communicate independently of the neural network but the speed is far slower within astrocytes although they complement the neuron transmissions. They also tend to be ever present in and around synaptic connections.

Oligodendrocytes are the most abundant of the Glial cells numbering over 50 to 1 over the neuron cells. They are most abundant as an outgrowth creating the myelin sheath separated by nodes of Ranvier. The Glial cells also show to bind groups of axons and support a structure for the collective.

Is this OK?

Moonbear

You mostly have the information correct, but some of the information is a bit incorrect, or not current.

You were misinformed here. Monocytes and macrophages are types of white blood cell involved in the immune system, and they are entirely unrelated to glial cells. Glial cells are formed in the brain from glial progenitor cells. They are not formed in the bone marrow at all.

That's what people used to think. However, more current research indicates that glia can release neurotransmitters.

That depends on what you mean by "fixed." Extension and retraction of glial cells continues in the mature cells. As for mitotic ability, other than some radial glia and the glial progenitor cells, glial cells, like neurons, are non-mitotic (at least to the best of my knowledge...there may be something out saying otherwise that I'm unaware of - neuroscience is not a small field and there's too much literature for any one person to keep up with all of it).

Potassium, sodium and calcium (Ca) ions are essential for all cells to function properly. Carbon (C) is the primary backbone of the vast majority of molecules in organisms (there are a few molecules that have biological activity that do not contain carbon, such as nitric oxide). I'm not sure if you really meant carbon, or abbreviated calcium incorrectly.

The rest sounds reasonably correct. One could argue oligodendrocytes appear somewhat star-shaped too when in culture, but that's minor and not really something to quibble over. There are other glial cells too, generally they are pretty specialized and located only in specific places in the brain, such as tanycytes in the mediobasal hypothalamus. But, generally, people focus on astrocytes and oligodendrocytes as the most abundant and ubiquitous.

Taoist

No unfortunately your not current, sir.
I beg to differ since I am not well versed in certain areas but the molecular level is where they are simpler. The protein NADPH is an oxidizer in the worse way. This protein is in both and it why I couple the two and so do others.

Oct 2005 Publication

http://www.ncbi.nlm.nih.gov/entrez/q...&dopt=Abstract

Expression and modulation of an NADPH oxidase in mammalian astrocytes.
Thus, the NADPH oxidase is expressed in astrocytes and is functional, activated by PKC and intracellular calcium, modulated by pHi, and upregulated by astrocyte activation. The astrocytic NADPH oxidase is likely to play important roles in CNS physiology and pathology

IN other words they see the pattern but have still yet to determine the full purposes.

Or to see another

http://www.ncbi.nlm.nih.gov/entrez/q...&dopt=Abstract

this shows a high oxidation molecule that offer a similarity to the white blood


Not neuron transmitters but burst of high energy as the above describes as oxidations. These energy bursts do a few things break down unwanted enzymes as white blood cells do and reinforce or support as glial, thus far in this discussion.

These cells are very important in many areas of the body and have more than just a few functions and my point still stands regarding memories but we need to get by these basics.

Moonbear

Will you please stop calling me sir!

You can beg all you want, but your information is still incorrect. NADPH is found in many cells; it does not make them related. Others do not couple them, nor do either of your references support that. The immune system and nervous system interact, as do all systems, but that's all that your second reference indicates.


No, you are just plain blatantly wrong here. I've already explained the current science to you, and you're just rejecting it out of hand. I'm not going to continue wasting my time trying to explain the science to you when it's clear you have no intention of coming here to learn.