Haloperidol blocks the conditioned place preferences induced by rewarding brain stimulation

The conditioned place preference test was employed to investigate the effects of neuroleptic challenge on the rewarding properties of lateral hypothalamic stimulation. Conditioning took place during a single day and consisted of five 5-min exposures to each of two environments (differing in color and floor texture). Twenty-four hours later, when provided a choice between the two environments, rats showed strong preferences for the environment in which they had experienced sessions of rewarding brain stimulation. These stimulation-produced place preferences were prevented by pretreatment with the neuroleptic drug, haloperidol (0.3 but not 0.15 mg/kg, ip). On the basis of these results, it was concluded that (a) the conditioned place preference test can provide a rate-free index of brain stimulation reward and (b) dopamine receptor antagonism can result in an attenuation of the rewarding properties of lateral hypothalamic stimulation.