Sensitization of hypervigilance effects of cocaine can be induced by NK3 receptor activation in marmoset monkeys

Background: Cocaine is a widely abused drug which can result in the establishment of addiction. The neurokinin3-receptor (NO-R) has been linked to cocaine addiction by genetic, epigenetic, and pharmacological studies suggesting that a cocaine-induced increase in NK3-R signaling may contribute to the establishment of cocaine addiction-related behaviors. Methods: Here we measured cocaine-induced sensitization of vigilance- and locomotor behaviors in marmoset monkeys (Callithrix penicillata) in an open field. Results: We found a sensitization of vigilance-related, but not locomotor behaviors after repeated cocaine (7 mg/kg, i.p.) treatment. There was a cross-sensitization for scan frequency, but not of glance frequency, both vigilance-related behaviors, after repeated treatment with the NK3-R agonist senktide (0.2 mg/kg, i.p.) given for 7 days, after a cocaine challenge (5 mg/kg, i.p.). Conclusions: These data suggest that in marmoset monkeys, repeated cocaine treatment leads to a sensitization of vigilance-related behaviors, which have a prominent role in spontaneously expressed activities in this species, but not of locomotor activity. Repeated activation of NK3-Rs can mimic some of the behavioral sensitization effect and may thus contribute to the establishment of cocaine related behaviors. (C) 2012 Elsevier Ireland Ltd. All rights reserved.