Loading...
Marijuana lowers the threshold for schizophrenia symptoms (NEJM JW Psychiatry Oct 2015 and JAMA Psychiatry 2015; 72:994). To investigate why, Canadian researchers studied the interaction of cannabinoid and glutaminergic signaling systems in a series of rat experiments.
The experiments involved cannabinoid 1 receptor (CB1R) agonism and antagonism and NMDA/AMPA receptor antagonism as the rats underwent fear conditioning, reward conditioning, and social preference tests. Stimulation of CB1Rs in the ventral hippocampus increased neuronal activity in the shell region of the nucleus accumbens via glutaminergic connections. This enhanced activity resulted in alteration of the salience of cues to punishment and reward, and that salience was dependen…