Fig. 14.

Optogenetic stimulation or inhibition of RMTg projections to the VTA drives real-time place aversion or preference, respectively, in transgenic Vgat-ires-Cre mice. a. As compared to the baseline amount of time spent in the laser-paired chamber (when no laser was delivered), ChR2-induced stimulation of RMTg projections to the VTA caused real-time avoidance of the light-paired chamber (n=7), while ArchT-induced inhibition of the RMTg-VTA pathway led to a strong real-time preference for the light-paired chamber (n=5). On the final test, no laser was delivered. *p<0.05, **p<0.01, ***p<0.001, ****p<0.0001 in post hoc analysis, as compared to baseline. b. Representative image of virus expression (mCherry) in the RMTg of Vgat-ires-Cre mice. c. Representative image of virus expression (mCherry visualized with DAB) in RMTg axon terminals within the VTA, and the location of bilateral optic fibers aimed at the VTA. d-g. Representative photos show Cre-dependent virus expression (mCherry) in FoxP1-labeled neurons in the RMTg of Vgat-ires-Cre mice (images are from region shown in g). h-k. Virus expression (mCherry) was also observed in axon terminals within VTA, but was not observed in TH-labeled or other cell bodies within VTA (images are from region shown in k). Scalebars = 50 μm for d-f and h-j, and 1 mm for g and k.