[Abstract Title]. - Society for Neuroscience

Abstract: The hypocretin/orexin (HCRT) system has recently been implicated in the regulation
of reinforcement and addiction processes, likely via actions on the mesolimbic dopamine (DA)
system. For example, HCRT infusions increase the firing rate of ventral tegmental DA neurons,
and the HCRT1 receptor antagonist SB-334867 blocks reinstatement of extinguished cocaineseeking
and locomotor sensitization to cocaine. In addition, we have shown that microdialysis
measures of cocaine-induced elevations in tonic DA signaling are reduced in rats pretreated with
SB-334867.
To further assess the relationship between the HCRT system and reinforcement processing, the
current studies sought to examine the extent to which HCRT neurotransmission regulates
behavioral and neurochemical responses to cocaine. Specifically, these studies utilized: 1) a
combination of discrete trials and progressive ratio self-administration procedures to assess
whether the HCRT 1 receptor antagonist, SB-334867, reduces cocaine intake; and 2) in vivo fast
scan cyclic voltammetry to test the extent to which SB-334867 infusions into the ventral
tegmental area attenuate cocaine-induced changes in phasic DA signaling within the NAc core.
Results indicate that SB-334867 reduces cocaine intake on both self-administration schedules
and attenuates cocaine-induced increases in DA signaling when injected into the VTA. These
observations offer additional support for the hypothesis that HCRT neurotransmission
participates in reinforcement and addiction processes through actions on the mesolimbic DA
system.
Disclosures: R.A. Espana , None; J.L. Locke, None; D.C.S. Roberts, None; S.R. Jones,
None.
Poster
298. Neural Mechanisms of Reward: Self-Administration and Opioid Modulation
Time: Sunday, November 16, 2008, 1:00 pm - 5:00 pm
Program#/Poster#: 298.4/TT37
Topic: F.03.d. Reward
Support: NIH grant DA14245
NIH grant DA00436
Title: Galanin modulates cocaine self-administration and locomotor activation
Authors: *C. P. BRABANT 1,2 , A. S. KUSCHPEL 1 , R. C. STEINER 1 , M. R. PICCIOTTO 1 ;
1 Yale Univ., New Haven, CT; 2 Univ. de Liège, Liège, Belgium