Hippocampal input to the nucleus accumbens reinforces behavior and drives cocaine-induced locomotion

Thursday, October 11, 2012 — Poster Session IV
2:00 p.m. – 4:00 p.m.	Natcher Conference Center, Building 45	NIDA	NEURO/BEHAV/SENSYS-3

* FARE Award Winner

Authors

• JP Britt
• F Benaliouad
• RA McDevitt
• GD Stuber
• RA Wise
• A Bonci

Abstract

The nucleus accumbens (NAc) facilitates reward seeking by exploiting reward-associated cues. Its distinct glutamatergic inputs, which debatably encode descriptive features of the environment, can elicit different physiological responses in the NAc and distinctive behaviors. In search of mechanistic explanations for these pathway-specific effects, we compared the innervation patterns and synaptic properties of major glutamatergic inputs. Here, hippocampal synapses were found to be uniquely concentrated in the medial NAc shell, where they were predominant and selectively potentiated following cocaine exposure. The behavioral consequence of this pathway was then examined with bidirectional optogenetic manipulations, which either attenuate or exaggerate cocaine-induced locomotion. Challenging the idea that glutamate afferents encode motivationally-neutral information, selective activation of hippocampal input produced a real-time place preference and reinforced instrumental behavior. Finally, optical activation of medium spiny neurons proved capable of supporting self-stimulation, demonstrating that behavioral reinforcement is a direct consequence of excitatory input to the NAc.

back to top