High Gamma Stimulation (80 Hz) Optical Stimulation of the IL-NAcSh Pathway Alters Innate but not Learned Aversion in Female Rats

The infralimbic cortex (IL) to nucleus accumbens shell (NAcSh) circuit is implicated in hedonicprocessing. Our lab established that 20 Hz optical stimulation of this pathway reducedconditioned taste aversion (CTA) in male rats, but not females. Additionally, local field potential(LFP) activity in the IL and NAcSh, and its functional connectivity, was selectively restricted to thehigh gamma frequency range (70-90 Hz) during innate and learned aversion in females. Here, weexamined if 80 Hz optical stimulation could alter innate and/or learned aversion in female rats.Results showed that 80 Hz stimulation of the IL-NAcSh pathway had no effect on CTA butsignificantly decreased appetitive and aversive responses (primarily during the first 5 minutes ofthe session), and increased neutral responses, during quinine exposure. These findings indicatethat the IL-NAcSh pathway is not involved in learned aversion but may play a role in mediatinginnate aversion in females.