TY - JOUR T1 - Cocaine experience abolishes the motivation suppressing effect of CRF in the ventral midbrain JF - bioRxiv DO - 10.1101/655936 SP - 655936 AU - Idaira Oliva AU - Melissa M. Donate AU - Merridee J. Lefner AU - Matthew J. Wanat Y1 - 2019/01/01 UR - http://biorxiv.org/content/early/2019/06/19/655936.abstract N2 - Stress affects dopamine-dependent behaviors in part through the actions of corticotropin releasing factor (CRF) in the ventral tegmental area (VTA). For example, acute stress engages CRF signaling in the VTA to suppress the motivation to work for food rewards and promote drug seeking behavior. These diverging behavioral effects in food- and drug-based tasks could indicate that CRF modulates goal-directed actions in a reinforcer-specific manner. Alternatively, prior drug experience could functionally alter how CRF in the VTA regulates dopamine-dependent behavior. To address these possibilities, we examined how intra-VTA injections of CRF influenced cocaine intake and whether prior drug experience alters how CRF modulates the motivation for food rewards. Our results demonstrate that intra-VTA injections of CRF had no effect on drug intake when self-administering cocaine under a progressive ratio reinforcement schedule. We also found that a prior history of either contingent or non-contingent cocaine infusions abolished the capacity for CRF to reduce the motivation for food rewards. Furthermore, voltammetry recordings in the nucleus accumbens illustrate that CRF in the VTA had no effect on cocaine-evoked dopamine release. These results collectively illustrate that exposure to abused substances functionally alters how neuropeptides act within the VTA to influence motivated behavior. ER -