A five-minute, but not a fifteen-minute, conditioning trial duration induces conditioned place preference for cocaine administration into the olfactory tubercle

The establishment of conditioned place preference (CPP) with intracranial injections requires specific injection sites, drug doses, and conditioning trial durations. We examined the role of conditioning trial duration in CPP with cocaine injections into the medial olfactory tubercle. Only those rats that had spent 5 min in the compartments showed CPP for cocaine, while rats that had been removed immediately or spent 15 min following cocaine injections did not show CPP. Effective conditioning trial durations for CPP induced by intracranial cocaine injections are apparently much shorter than those typically used for intracranial injections of other drugs of abuse.