Mechanism explains complex brain wiring

How neurons are created and integrate with each other is one of biology's greatest riddles. Researcher Dietmar Schmucker from VIB-KU Leuven unravels a part of the mystery in Science magazine. He describes a mechanism that explains novel aspects of how the wiring of highly branched neurons in the brain works. These new insights into how complex neural networks are formed are very important for understanding and treating neurological diseases.

Neurons, or nerve cells

It is estimated that a person has 100 billion , or . These neurons have thin, elongated, highly branched offshoots called dendrites and axons. They are the body's information and signal processors. The dendrites receive electrical impulses from the other neurons and conduct these to the cell body. The cell body then decides whether stimuli will or will not be transferred to other cells via the axon.

The brain's wiring is very complex. Although the molecular mechanisms that explain the linear connection between neurons have already been described numerous times, little is as yet known about how the branched wiring works in the brain.

The connections between nerve cells

Prior research by Dietmar Schmucker and his team lead to the identification of the Dscam1 protein in the fruit fly. The neuron can create many different protein variations, or isoforms, from this same protein. The specific set of isoforms that occurs on a neuron's cell surface determines the neuron's unique molecular identity and plays an important role in the establishment of accurate connections. In other words, it describes why certain neurons either come into contact with each other or reject each other.

Recent work by Haihuai H and Yoshiaki Kise from Dietmar's team indicates that different sets of Dscam1 isoforms occur inside one axon, between the newly formed offshoots amongst each other. If this was not the case, then only linear connections could come about between neurons. These results indicate for the first time the significance of why different sets of the same protein variations can occur in one neuron and it could explain mechanistically how this contributes to the complex wiring in our brain.

Clinical impact

Although this research was done with fruit flies, it also provides new insights that help explain the wiring and complex interactions of the human brain and shine a new light on neurological development disorders such as autism. Thorough knowledge of nerve cell creation and their neural interactions is considered essential knowledge for the future possibility of using as standard treatment for certain nervous system disorders.

More information: "Cell-intrinsic requirement of Dscam1 isoform diversity for axon collateral formation." Haihuai He, Yoshiaki Kise, Azadeh Izadifar, Olivier Urwyler, Derya Ayaz, Akhila Parthasarthy, Bing Yan, Maria-Luise Erfurth, Dan Dascenco, and Dietmar Schmucker. Science 6 June 2014: 344 (6188), 1182-1186.Published online 15 May 2014. DOI: 10.1126/science.1251852

add to favorites email to friend print save as pdf

Related Stories

How neurons get wired

Aug 14, 2013

Two different versions of the same signaling protein tell a nerve cell which end is which, UA researchers have discovered. The findings could help improve therapies for spinal injuries and neurodegenerative ...

Recommended for you

User comments

Adjust slider to filter visible comments by rank

Display comments: newest first

JVK
1 / 5 (4) Jun 12, 2014
Unless nerve cell CREATION results from mutations, which is biologically improbable, it is nutrient-dependent and pheromone-controlled via the epigenetic effects of food odors and pheromones associated with nutrient stress and social stress and alternative splicings of pre-mRNA (e.g., microRNAs) that allow fixed amino acid substitutions to stabilize the organized genome in species from microbes to man.

Cell type differentiation of stable nerve cells is not likely to be due to anything other than the conserved molecular mechanisms that enable ecological, social, neurogenic, and socio-cognitive niche construction manifested in the morphological and behavioral phenotypes associated with cell type differentiation and increasing organismal complexity in all species.

Increasing organismal complexity is not likely to be due to mutations that perturb protein folding.

Nutrient-dependent/pheromone-controlled adaptive evolution: a model
http://www.ncbi.n...3960065/
Captain Stumpy
5 / 5 (1) Jun 14, 2014
results from mutations, which is biologically improbable
@jk
so you are saying that THIS
Nutrient-dependent/pheromone-controlled adaptive evolution: a model
is now BIOLOGICALLY IMPROBABLE...
wow...
first you say mutations are bad,
then you post a model that CREATES MUTATIONS AND SUPPORTS MUTATIONS IN EVOLUTION...
which is it jk?
mutations or mutations?
no wonder you are considered a pseudoscience crackpot. remember when we talked about mutations?I asked
DOES your model make any changes to the nucleotide sequence of the genome of an organism, virus, or extrachromosomal genetic element?
This is a yes or no answer
to which you answered
YES!
--Thanks for asking
so, drawing from your own words AGAIN...
IF mutations are BAD AND you say yourself that your model causes mutations THEN one can only conclude that YOU are an IDIOT and you DON'T KNOW WHAT YOU ARE TALKING ABOUT!
YOUR WORDS,
YOU said it... again... not someone else
YOU
JVK
1 / 5 (3) Jun 14, 2014
http://www.bsd-jo...nt/5/1/8

"...the emergence of sex differences in the brain may be a gradual process that is cemented over the organism's life. Our data provide a new perspective by showing that most sex differences in CpG methylation are dynamic and not the result of acute modifications in response to hormones."

Only an idiot would continue to insist that mutations cause sex differences in cell types or any other differences in cell types in any individual of any species. The differences are nutrient-dependent and pheromone-controlled.

Nutrient-dependent/pheromone-controlled adaptive evolution: a model. http://www.ncbi.n...24693353
Captain Stumpy
5 / 5 (2) Jun 14, 2014
Nutrient-dependent/pheromone-controlled adaptive evolution: a model.
this model CREATES MUTATIONS
therefore, per your own words, the AUTHOR of this model is an idiot, right?
why do you spam the site with the same crap over and over?
especially knowing full well that THE ABOVE MODEL is PROOF that MUTATIONS CAN CAUSE SPECIES DIVERSITY AND ADAPTABILITY and therefore THEY CAN BE BENEFICIAL and it SUPPORTS EVOLUTION THEORY every bit as much as Lenski does!

YOUR MODEL PROVES THAT MUTATIONS CAN BE BENEFICIAL which is CONTRARY to your stance about mutations, which means YOU DON'T KNOW WHAT YOU ARE TALKING ABOUT

Myers was right... you really ARE unstable and incapable of seeing the reality standing before you!
JVK
1 / 5 (3) Jun 14, 2014
In my comment to Science (AAAS) http://comments.s....1252806 I wrote:

"The likelihood that species-specific pheromones control the physiology of reproduction in species from microbes to man suggests that attributing the evolution of any organ to a mutation is a misatribution. The misatribution appears to support a theory invented by population geneticists to explain what is actually nutrient-dependent pheromone-controlled biodiversity.

If the rumen is an ecological adaptation, any suggestion that it exemplifies mutation-driven evolution is one that can now be challenged by experimental evidence from the extant literature on how the nutrient-dependent microRNA/messenger RNA balance contributes to cell type differentiation in individuals of all species."

If you find other studies that report what appears to be mutation-driven evolution published in Science or Nature or Cell, I may comment on how ridiculous their misrepresentations are, too.
JVK
1 / 5 (3) Jun 14, 2014
Myers was right... you really ARE unstable and incapable of seeing the reality standing before you!


For those of you who don't know it, PZ Myers is the atheist blogger and idiot biology teacher who got his idiot minions to believe that mutations cause species diversity and that nutrient-dependent pheromone-controlled chromosomal rearrangements do not.

See http://www.scienc...2201.htm "The chromosomes are then able to find their suitable partner during meiosis, allowing the plants to stay fertile and a new species is generated." For an example from vertebrates see: http://phys.org/n...eld.html

For examples of pseudoscientific nonsense taught to anyone with the potential to become an idiot minion but still try to live in the real world, see:

http://freethough...t-737848

and other blog posts by PZ Myers
Captain Stumpy
5 / 5 (2) Jun 15, 2014
If you find other studies that report what appears to be mutation-driven evolution published in Science or Nature or Cell, I may comment on how ridiculous their misrepresentations are, too
@jk
well, I can guarantee that you will want to talk to THIS particular author, because he completely talks about mutation EVERY TIME he posts! https://sciencex....ser/JVK/
You see... his model is being posted ad nauseum in an attempt to discredit the theory of evolution, however it actually SUPPORTS it! THIS AUTHOR PROMOTES MUTATIONS WITH HIS MODEL so you had better set him straight!

remember when we talked about mutations?I asked
DOES your model make any changes to the nucleotide sequence of the genome of an organism, virus, or extrachromosomal genetic element?
This is a yes or no answer
to which you answered
YES!
--Thanks for asking
so for you to now say what you did above only CONFIRMS that you are an idiot and YOU DON'T KNOW WHAT YOU ARE TALKING ABOUT
Captain Stumpy
5 / 5 (2) Jun 15, 2014
For those of you who don't know it, PZ Myers is the atheist blogger and idiot biology teacher who got his idiot minions to believe that mutations cause species diversity
@jk
ACTUALLY... J.Kohl is the author that cemented the fact that mutations cause diversity in my opinion! especially based upon our past conversations! remember when we talked about mutations?I asked
DOES your model make any changes to the nucleotide sequence of the genome of an organism, virus, or extrachromosomal genetic element?
This is a yes or no answer
to which you answered
YES!
--Thanks for asking
so if you are now saying that mutations do NOT cause diversity, then we can PROVE that:
1- YOU DONT KNOW WHAT YOU ARE TALKING ABOUT
2- YOU LIE
3- YOU DONT UNDERSTAND THE LEXICON OF YOUR OWN FIELD
4- YOU OBVIOUSLY ARE AN IDIOT, especially considering that you've been shown the error of your ways here: http://freethough...s-place/
alfie_null
5 / 5 (2) Jun 15, 2014
http://freethoughtblogs.com/pharyngula/2014/01/06/one-crank-dies-another-rises-to-take-his-place/

Thank you for the link. An informative, entertaining and well written blog. Bits like "He crashes into a thread full of lay people and then lords it over them with his abuse of jargon." certainly ring true. Didn't know he sells perfume. Guess that explains the bias/obsession with pheromones.
JVK
1 / 5 (3) Jun 15, 2014
http://dx.doi.org...jn.12539 Behavior is receptor-mediated. If you can convince people it is not receptor-mediated, you can probably convince them that the different morphological and behavioral phenotypes of species from microbes to man somehow evolved via mutations and natural selection. However, without the nutrient-dependent pheromone-controlled de novo creation of olfactory receptor genes, ecological variation could not possibly result in the ecological adaptations some people think are the result of mutation-driven evolution.
Captain Stumpy
5 / 5 (1) Jun 17, 2014
somehow evolved via mutations and natural selection
@jk
why do you keep doing this? it is ridiculous! YOUR MODEL CREATES MUTATIONS, and therefore YOUR MODEL SUPPORTS EVOLUTION as well as
mutation-driven evolution
GIVEN that your model creates mutations
and given that it supports evolution
THEN any statements that you have against mutation driven evolution are AGAINST YOUR OWN MODEL
THEREFORE we can conclude that you
1-DONT KNOW WHAT YOU ARE TALKING ABOUT
2-CANNOT COMPREHEND YOUR OWN FIELD
3-DO NOT COMPREHEND THE LEXICON OF YOUR FIELD
4-ARE STUPID as you HAVE learned this all in the past, from many posters here as well as biologists elsewhere (Myers comes to mind)

I would continue, but this is really redundant. you will only post a bunch of irrelevant BS or studies that you misunderstood which support me without you even realising it.
no wonder you've been banned from logical discourse at Myers page...You absolutely CANNOT SEE EMPIRICAL DATA IN YOUR FACE

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.