Posted by SLS on November 19, 2013, at 7:05:39
In reply to Are you sure NAC is anti-glutamate?, posted by Lamdage22 on November 19, 2013, at 4:08:17
> I read that it releases glutamate into extracellular space.
NAC is being used as a glutamatergic modulator at Harvard / Massachusetts General to treat stubborn cases of depression and bipolar disorder.
I am guessing that you saw this article. Here, the excess *extrasynaptic* glutamate acts on glutamate *autoreceptors* along the neuron that, when stimulated, inhibit the release of *intrasynaptic* glutamate. Stimulating autoreceptors usually inhibits synthesis and release of neurotransmitters.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3044191/
- Scott-------------------------------------------------------
N-acetylcysteine in psychiatry: current therapeutic evidence and potential mechanisms of action
Glutamate
In addition to the effects on oxidative balance, alterations in cysteine levels have also been shown to modulate neuro-transmitter pathways, including glutamate and dopamine (DA; Fig. 1).23,24 Cysteine assists in the regulation of neuronal intra- and extracellular exchange of glutamate through the cystineglutamate antiporter. Whereas this antiporter is ubiquitous throughout all cell types, in the brain it is preferentially located on glial cells.25 The dimer, cystine, is taken up by astrocytes and exchanged for glutamate, which is released into the extracellular space.
...* This free glutamate appears to stimulate inhibitory metabotropic glutamate receptors on glutamatergic nerve terminals and thereby reduce the synaptic release of glutamate. *...
Given that relation, the amount of cysteine in the system as well as the feedback via GSH production by neurons may directly regulate the amount of glutamate present in the extracellular space. Furthermore, GSH itself has been shown to potentiate brain N-methyl-d-aspartate receptor response to glutamate in rats.27,28 Changes in the levels of neuronal GSH may not only alter available glutamate levels, but also have direct consequences on glutamatergic function.
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Some 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:1054471
URL: http://www.dr-bob.org/babble/20131115/msgs/1054600.html