Effects of single and long-term haloperidol administration on open field behavior of rats.

The effects of single and long-term haloperidol administration on rat open field behavior was studied. Withdrawal from long-term haloperidol treatment induced a significant increase in all parameters of activity recorded, except rearing. There was a direct relationship between the impairment of motor function induced by the single haloperidol administration and the increment of general activity observed after withdrawal from repeated drug administration. The results were considered to be a consequence of the supersensitivity of central dopaminergic receptors probably, of the mesostriatal pathway, that occurred in order to maintain the animal's homeostasis.