Brain regions associated with inverse incentive learning: c-Fos immunohistochemistry after haloperidol sensitization on the bar test in rats

•We pair low-dose of haloperidol with the environment of a bar test.•Pairing daily haloperidol with the bar test produces sensitized descent latencies.•Unpaired rats received haloperidol in their home cages; they did not sensitize.•Paired rats have less c-Fos in the nucleus accumbens core and ventral pallidum.•Paired and unpaired have less c-Fos in the striatum and nucleus accumbens shell.