Fig. 2
From: Nucleus accumbens medium spiny neurons subtypes signal both reward and aversion
Brief and prolonged D1- and D2-MSN stimulation differentially modulate cocaine conditioning. a Representation of the CPP cocaine 5 mg/kg + optical stimulation (1 s or 60 s) paradigm. b Cocaine induces preference in all groups as expected; and brief optical activation of D1- or D2-MSNs further enhances cocaine reinforcing effects (c). In comparison with eYFP groups, D1-ChR2 or D2-ChR2 spend more time in the cocaine + brief stimulus chamber (nD1-eYFP = 6, nD1-ChR2 = 9; nD2-eYFP = 5, nD2-ChR2 = 9). d Cocaine induces preference in all groups. Prolonged optical activation of D1-MSNs does not change the reinforcing properties of cocaine, whereas D2-MSN prolonged stimulation decreases cocaine reward (e) (nD1-eYFP = 6, nD1-ChR2 = 9; nD2-eYFP = 6, nD2-ChR2 = 9). **p < 0.01, ***p < 0.001. Data are represented as mean ± SEM
