PT  - JOURNAL ARTICLE
AU  - Idaira Oliva
AU  - Melissa M. Donate
AU  - Merridee J. Lefner
AU  - Matthew J. Wanat
TI  - Cocaine experience abolishes the motivation suppressing effect of CRF in the ventral midbrain
AID  - 10.1101/655936
DP  - 2019 Jan 01
TA  - bioRxiv
PG  - 655936
4099  - http://biorxiv.org/content/early/2019/05/31/655936.short
4100  - http://biorxiv.org/content/early/2019/05/31/655936.full
AB  - Stress affects dopamine-dependent behaviors in part through the actions of corticotropin releasing factor (CRF) in the ventral tegmental area (VTA). In particular, CRF signaling in the VTA mediates how acute stress suppresses the motivation to work for food rewards, as well as how stress promotes 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.