And Matt Spitzer answers:
Benzodiazepines work by potentiating GABAergic synaptic transmission, so I
suppose the "endogenous benzodiazepine" would be GABA.
I agree about the effects of benzodiazepins on the GABA receptor complex, a
potentiation. However, I strongly hesitate to consider GABA as "endogenous
benzodiazepine".
Peter Laudrup
laudrup at osu.edu