Fig. 1
From: Nucleus accumbens medium spiny neurons subtypes signal both reward and aversion
Bidirectional effect of NAc D1- and D2-MSNs in reinforcement. a Strategy used for optogenetic manipulation. A cre-dependent ChR2 or eYFP was injected unilaterally in the NAc of D1-cre or D2-cre transgenic mice. b Representative immunofluorescence of eYFP and D1R (left panel) or D2R (right panel). c Schematic representation of optogenetic stimulation parameters in the CPP test (1 s or 60 s of 12.5 ms pulses at 40 Hz). d Brief (1 s) optical stimulation of NAc D1- or D2-MSNs induces place preference (nD1-eYFP = 8, nD1-ChR2 = 7; nD2-eYFP = 8, nD2-ChR2 = 9). e Increased preference for the stimulus-associated chamber (ON) in all D1-ChR2 and D2-ChR2 animals. f Prolonged (60 s) optical stimulation of NAc D1- or D2-MSNs induces aversion (nD1-eYFP = 8, nD1-ChR2 = 7; nD2-eYFP = 8, nD2-ChR2 = 9). g Aversion to the ON chamber in D1-ChR2 and D2-ChR2 animals. h Schematic representation of the real-time preference apparatus. Whenever animals are on the “ON chamber”, they receive optogenetic stimulation (12.5 ms pulses at 40 Hz) that ceases only when animals cross to the OFF side. Representative track of (i) D1-ChR2 and D1-eYFP animals, and (j) D2-ChR2 and D2-eYFP animals. k, l Both D1-ChR2 and D2-ChR2 mice spent less time in the stimulus-associated box (nD1-eYFP = 7, nD1-ChR2 = 8; nD2-eYFP = 8, nD2-ChR2 = 9). *p < 0.05, **p < 0.01, ***p < 0.001. Data are represented as mean ± SEM
