The aim of this project is to determine the role of striatal dopamine release in motivation and reinforcement. Recently, we found that chemical stimulation of the supramammillary nucleus is reinforcing in rats, suggesting that the supramammillary nucleus may be a component of primary reinforcement. Since dopamine release in the ventral striatum has been implicated in primary reinforcement, we examined whether electrical stimulation of supramammillary nucleus is reinforcing and evokes dopamine release in the ventral striatum as shown by voltammetric signals. Rats learned to lever-press to deliver brief trains of electrical stimulation at the supramammillary nucleus with currents around 200 micro A. Electrical trains that support vigorous self-stimulation at the supramammillary area induced dopamine released as indicated by voltammetric signals. Temporal patterns of dopamine signals evoked by supramammillary stimulation are essentially identical to those of evoked by ventral tegmental stimulation. These results suggest that supramammillary stimulation triggers dopamine release in the ventral striatum, which has been implicated in primary reinforcement, and that the supramammillary nucleus is part of the reward circuitry associated with the meso-limbic dopamine system.

Agency
National Institute of Health (NIH)
Institute
National Institute on Drug Abuse (NIDA)
Type
Intramural Research (Z01)
Project #
1Z01DA000482-02
Application #
7321129
Study Section
(BN)
Project Start
Project End
Budget Start
Budget End
Support Year
2
Fiscal Year
2006
Total Cost
Indirect Cost
Name
National Institute on Drug Abuse
Department
Type
DUNS #
City
State
Country
United States
Zip Code
Blanco, Carlos; Potenza, Marc N; Kim, Suck Won et al. (2009) A pilot study of impulsivity and compulsivity in pathological gambling. Psychiatry Res 167:161-8