Fig. 1: VTADA activity and GABA input during punishment learning.
a TH::Cre+ rats received Cre-dependent calcium or GABA sensors and fiber implant into VTA. b Punishment task. Rats could press two levers (R1, R2 [5 min alternating blocks]) for food. In punishment sessions, R1 responses also yielded footshock (FR10 schedule). During choice test, both levers were presented to assess lever preference. c Timeline of task sessions. d Mean ± SEM lever-press ratios for the last session of lever training (T), punishment sessions (1-6) and choice (C) across subjects (N = 14). Punishment led to robust, selective suppression of R1 responding, and a strong preference for unpunished R2 over previously-punished R1 during choice test. e Example GCaMP expression and fiber placement. f Placement map for rats with valid GCaMP and fiber tip locations (n = 7). g Example iGABASnFR expression and fiber placement. h Placement map for rats with valid iGABASnFR and fiber tip locations (n = 10). i, j Mean ± SEM of subject-averaged VTA GCaMP I and iGABASnFR J signals around response-elicited appetitive and aversive outcomes (pellet delivery [teal] vs. footshock [purple]) during lever training, early punishment (Pun 1 [1st session]), late punishment (sessions 4 + ), and choice sessions. Vertical dashed lines indicate event onset (yellow highlighted area indicates shock duration). Horizontal dotted line indicates pre-event baseline. Bars at the bottom indicate when peri-event signals significantly deviated from baseline, and when pellet-related and shock-related signals significantly differed from each other (orange bars). Appetitive and aversive events elicited increases in VTADA activity and GABA input, but GABA input tended to be greater for aversive events, while increases in VTADA activity were greater for rewards. k, l Mean ± SEM of subject-averaged VTA GCaMP k and iGABASnFR l signals around R1 vs. R2 actions (action alone; no outcomes delivered) for lever training, early punishment (Pun 1), late punishment, and choice sessions. Vertical dashed lines indicate time of lever-press. Bars at the bottom of each panel indicate when action-related signals significantly deviated from pre-event baseline (horizontal dashed line), and when action signals significantly differed from each other (orange bars). VTADA activity to punished R1 actions became dissociated from unpunished R2 actions as punishment was learned. GABA input to VTADA did not significantly distinguish between actions across punishment or choice.
