Posted by SLS on August 23, 2012, at 19:43:46
In reply to Can someone explain this in lay terms?, posted by gadchik on August 22, 2012, at 15:57:29
> "Neural stem cells seem to be particularly interested in the chemical GABA (gamma-aminobutyric acid) a neurotransmitter thats known to be involved in inhibiting signals from other neurons. When scientists artificially block these stem cells GABA receptors from receiving messages, the cells wake up and start replicating but when those GABA signals are allowed to reach the receptors, the stem cells stay dormant.
I don't know for sure, but I will venture a guess. I think we are looking at a negative feedback loop.
GABA is the most common inhibitory neurotransmitter in the brain. There are more GABA neurons than any other type (glutamate, dopamine, norepinephrine, serotonin, etc.) They are responsible for preventing overactivity of excitatory pathways. They act as "brakes". The brain must make sure that there are enough brakes to control and balance the system. New neurons come from stem cells. Stem cells can become any type of neuron, depending on what they are "told" to grow into (differentiation). If there is not enough GABA floating around, the stem cells are told to become GABA neurons. The way a stem cell knows that there isn't enough GABA is to have special receptors that "see" GABA molecules. If you "blind" those receptors to GABA by blocking them artificially, the stem cell thinks that there is insufficient GABA in the environment, and it therefore differentiates into a GABA neuron.
- ScottSome see things as they are and ask why.
I dream of things that never were and ask why not.- George Bernard Shaw
poster:SLS
thread:1023940
URL: http://www.dr-bob.org/babble/20120818/msgs/1024062.html