Congratulations to Emily Prevost and team on their pre-print Monosynaptic inputs to ventral tegmental area glutamate and GABA co-transmitting neurons. This work has been ongoing since we started the lab in 2018, which led us to develop SHARCQ for use here.
While the overall circuits of GABA-releasing or glutamate-releasing VTA neurons have been identified, the circuits of neurons that co-transmit glutamate and GABA are unknown. We used INTRSECT vectors, rabies tracing, and SHARCQ to identify the brainwide inputs to these co-transmitting neurons. Large numbers of inputs came from lateral hypothalamus and superior colliculus while the most dense inputs came from lateral habenula, dorsal raphe, and locally in the VTA. We hypothesized most inputs were glutamatergic and indeed found that lateral hypothalamus glutamate neurons as well as superior colliculus glutamate neurons functional activate VTA glutamate and GABA co-transmitting neurons. Activation of each neuron resulted in different behaviors related to threat interpretation but these behaviors did not correlate with VTA activity. We hypothesize that VTA glutamate and GABA co-transmitting neurons receive a general signal of threat via these pathways that does not involve the movements underlying the reaction to those threats. Finally, we supported that these neurons act as outcome detectors and the identified circuits here may be a mechanism by which they integrate information related to the detection and processing of motivationally-salient outcomes.
Check out the paper here
