Comment · Fri, November 22, 2013 · Ceretropic
Piracetam induces plasma membrane depolarization in rat brain synaptosomes
What they were answering
willonz · 1 points
Can you elaborate on the effect it has on GABA receptors? I assume it has to do with piracetam's effect on opening the GABA receptor allosterically (?), as the introduction of the GABA channel blocker reduced piracetam's effect.
What I'm failing to comprehend is that if piracetam is facilitating the expulsion of Cl- from the cell, this is not the conventional effect of Cl-. It most commonly has reduced concentrations in the cell, thus the opening of the pore will pull Cl- into the cell, resulting in hyperpolarization. Unless piracetam is only acting on the unconventional tissues where CL- is at higher concentrations intracellularly (interestingly enough, in hippocampal CA3 and hormonal pituitary areas), could piracetam also be a GABAr positive-modulator? (presumably at these tissues)
u/MisterYouAreSoDumb · Ceretropic
Well piracetam decreases GABA content in the cortex, which may sensitize GABA receptors. I do not think it acts directly on the GABA receptors themselves, even allosterically. However, it is possible there is some mechanism that is positively modulating the GABA system.
Piracetam seems to modulate the ion transporters, which expel Cl- out of the neuron, allowing for the cell to reach excitability faster than it normally would.