摘要：SummaryThe nucleus accumbens (NAc) plays a key role in drug-related behavior and natural reward learning. Synaptic plasticity in dopamine D1 and D2 receptor medium spiny neurons (MSNs) of the NAc and the endogenous cannabinoid (eCB) system have been implicated in reward seeking. However, the precise molecular and physiological basis of reward-seeking behavior remains unknown. We found that the specific deletion of metabotropic glutamate receptor 5 (mGluR5) in D1-expressing MSNs (D1miRmGluR5 mice) abolishes eCB-mediated long-term depression (LTD) and prevents the expression of drug (cocaine and ethanol), natural reward (saccharin), and brain-stimulation-seeking behavior.In vivoenhancement of 2-arachidonoylglycerol (2-AG) eCB signaling within the NAc core restores both eCB-LTD and reward-seeking behavior in D1miRmGluR5 mice. The data suggest a model where the eCB and glutamatergic systems of the NAc act in concert to mediate reward-seeking responses.Graphical AbstractDisplay OmittedHighlights•mGluR5-D1-CB1-induced eCB-LTD mediates drugs of abuse and natural reward seeking•eCB-LTD in D2-MSNs plays no important role in processing of reward-seeking responses•Loss of eCB-LTD is a consequence of higher MAGL activity and lower CB1R expression•Acute drug administration stops craving for alternative rewards on following daysNeuroscience; Behavioral Neuroscience; Molecular Neuroscience
