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5‐HT 1B receptors in nucleus accumbens efferents enhance both rewarding and aversive effects of cocaine
Author(s) -
Barot Sabiha K.,
Ferguson Susan M.,
Neumaier John F.
Publication year - 2007
Publication title -
european journal of neuroscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.346
H-Index - 206
eISSN - 1460-9568
pISSN - 0953-816X
DOI - 10.1111/j.1460-9568.2007.05568.x
Subject(s) - nucleus accumbens , neuroscience , receptor , psychology , 5 ht receptor , reward system , addiction , serotonin , dopamine , medicine
Whether serotonin‐1B (5‐HT 1B ) receptor activation enhances or diminishes the reinforcing properties of psychostimulants remains unclear. We have previously shown that increased expression of 5‐HT 1B receptors in nucleus accumbens (NAcc) shell neurons sensitized rats to the locomotor‐stimulating and rewarding properties of cocaine. In this study we further examined the contribution of 5‐HT 1B receptors on the effect of cocaine under conditions intended to selectively influence either conditioned place preference or avoidance (CPP or CPA, respectively). Viral‐mediated gene transfer techniques were used to overexpress 5‐HT 1B receptors in medial NAcc shell medium spiny neurons projecting to the ventral tegmental area. Animals were then conditioned to associate place cues with the effects of either a low (5 mg/kg) or moderately high (20 mg/kg) dosage of cocaine immediately or 45 min after intraperitoneal cocaine administration. Animals with increased 5‐HT 1B expression showed cocaine‐induced CPP immediately after administration of the low 5 mg/kg dose of cocaine, but a CPA 45 min after administration of the high 20 mg/kg dose. Control animals showed no preference at the 5 mg/kg dose and a significant preference at 20 mg/kg. Given this, we believe that increased 5‐HT 1B receptor activation in NAcc shell projection neurons intensifies both the rewarding and negative properties of cocaine use.