Temporal dynamics of frustration: Prefrontal oscillations and licking behavior during unexpected reward loss

Consummatory Successive Negative Contrast (cSNC) is characterized by reduced consumption following an unexpected reward loss. The resulting aversive emotional state is known as frustration. Although corticolimbic circuits are involved, it remains unclear whether their participation is immediate or emerges later. Examining the temporal dynamics of frustration may improve our understanding of mechanisms involved in its expression and recovery. In two experiments, rats performed a cSNC task with 5-min access to sucrose solution. In Exp. 1, licking was recorded with an automated system. In Exp. 2, LFP (Local Field Potential) were recorded from the anterior cingulate (ACC) and infralimbic (IL) cortices. Alpha (7–12Hz), beta (13–30Hz), and gamma (30–100Hz) activity were analyzed during the first postshift session. Our results show that downshifted rats significantly reduced licking relative to the unshifted group from the second minute onward. Furthermore, downshifted rats increased alpha and decreased beta and gamma activity from the first minutes in ACC and IL. Together, the parallel temporal evolution of licking behavior and prefrontal (PFC) oscillatory activity suggests that frustration emerges early after reward devaluation and that the ACC and IL may be involved in this response. Future studies should examine additional postshift days to characterize the neural dynamics of recovery and employ cell-specific manipulations in the PFC and amygdala to determine their causal roles.