We have studied the behavioral responses in open-field and the changes in body temperature induced after chronic treatment with a selective D1 antagonist,
SCH 23390, a selective D2+ antagonist,
sulpiride, or a non specific but preferential D2 antagonist,
haloperidol. After chronic treatment with
SCH 23390 or
sulpiride, rats were challenged with
SKF 38393, selective D1 agonist, or
LY 171555, selective D2 agonist, in order to study the responses of D1 and D2 stimulation. After chronic
SCH 23390, an increase of the locomotion and of the number of rears were observed whereas, no changes were induced by chronic
sulpiride or
haloperidol. Acute treatment with
sulpiride blocked the hyperlocomotion induced by chronic
SCH 23390. In naive rats acute administration of
SKF 38393 or
LY 171555 did not produce any change in locomotion or rearing. In rats treated chronically with
SCH 23390 this acute administration of
LY 171555 induced an increase of the number of squares and of the number of rears. In these animals, acute administration of
SKF 38393 also augmented the number of squares crossed. In contrast, chronic
sulpiride did not modify behavioral responses obtained after acute
SKF 38393 or
LY 171555. Colonic temperature was not changed after acute
SKF 38393 while acute
LY 171555 induced a
hypothermia. Chronic
sulpiride did not modify the responses of
SKF 38393 or
LY 171555, but an increase in body temperature was observed after acute
SKF 38393 in animals chronically treated with
SCH 23390. The present results support a different behavioral expression of D1 and D2 supersensitivity in rats. Furthermore, chronic treatment with a D1 antagonist induced facilitatory effects on D2 behavioral responses; however, these D1-D2 interactions were not observed in body temperature responses.