Endocannabinoids

"Brains make their own calming substances called cannabinoids, which are similar to marijuana's active ingredients."

wha, really? Never woulda guessed! Ah, maybe it really is useful information for some...it's sometimes hard to imagine that there's folks out there that don't know about G-protein coupled receptors if you're working with them every day.

WebMD

The actual study that the WebMD article refers to appears in Nature, and has to do with neocortical GABA interneurons. Self-inhibition in these cells depends on an endocannabinoid-dependent mechanism that leads to a reduction in firing rate. Quite interesting stuff since this would represent an expansion of the known roles of endocannabinoids and a relatively novel mechanism of neuronal self-inhibition.