Absence of Cocaine-induced Place Conditioning in Serotonin 1B Receptor Knock-out Mice

Stimulation of serotonin 1B receptors induces conditioned place aversion and facilitates cocaine place conditioning in rats

“…These results are in line with recent findings that pharmacological stimulation of 5-HT 1B receptors in rats enhances the rewarding properties in the self-administration procedure (Parsons et al 1998) and with the recent finding that 5-HT 1B knock-out mice show no CPP for stimuli paired with cocaine (Belzung et al 2000). Although self-administration and CPP may reflect different aspects of the central action of cocaine, the present study found that in appropriate conditions, 5-HT 1B -induced facilitation of cocaine rewarding effects can be seen in both models.…”

“…5-HT 1B knockout mice showed a shorter latency to meet intravenous cocaine self-administration criteria, as well as an increased breaking point for cocaine infusion in the progressive ratio schedule and increased propensity to self-administer cocaine (Rocha et al 1998;Castanon et al 2000). However, more recently using the conditioned place preference (CPP) paradigm, Belzung et al (2000) found that 5-HT 1B receptor knock-out mice failed to display a conditioned place preference for stimuli paired with cocaine. There are no simple explanations for these apparently contradictory results.…”

Rewarding effects elicited by cocaine microinjections into the ventral tegmental area of C57BL/6 mice: involvement of dopamine D1 and serotonin1B receptors

“…This increased expression was shown to result in sensitization of cocaine-induced place preference (Neumaier et al 2002). Mice lacking the gene for this receptor subtype failed to display any preference for stimuli paired with cocaine (Belzung et al 2000). However, they exhibited an increased locomotor response to this drug and appeared to be more motivated to self-administer it, thus suggesting an increased vulnerability to cocaine (Rocha et al 1997(Rocha et al , 1998a.…”

Pharmacological Evidence for an Abstinence-Induced Switch in 5-HT1B Receptor Modulation of Cocaine Self-Administration and Cocaine-Seeking Behavior

“…10,11 In contrast, in rats, 5-HT 1B receptor agonists shift the cocaine dose–effect function to the left on a fixed ratio (FR) schedule and increase cocaine intake on a PR schedule, suggesting that 5-HT 1B receptors enhance cocaine reinforcement and motivation for cocaine. 12−14 Additionally, 5-HT 1B receptor knockout mice do not display cocaine-conditioned place preference (CPP), 15 whereas in rats 5-HT 1B receptor agonists enhance cocaine-CPP but produce conditioned place aversion when administered alone. 16 5-HT 1B receptor agonists also elevate intracranial self-stimulation thresholds and prevent cocaine-induced decreases in intracranial self-stimulation thresholds, suggesting that these receptors inhibit cocaine reward.…”