SINGLE RESTRAINT STRESS SENSITIZES ACUTE CHEWING MOVEMENTS INDUCED BYHALOPERIDOL, BUT NOT IF THE 5-HT1A AGONIST 8-OH-DPAT IS GIVEN PRIOR TO STRESS

The objective of this study was two-fold: (i) to analyze behavioral se nsitization to haloperidol 2 weeks after single restraint stress, and (ii) to establish the effects of 8-OH-DPAT treatment prior to stress o n sensitized behavioral responses. Overall behavior was analyzed and n ot only catalepsy, but also sedation (immobility), grooming, explorati on and vacuous chewing movements were evaluated. Results indicated tha t single restraint stress induced a long-lasting sensitization of acut e vacuous chewing movements induced by haloperidol (0.25, 0.5 mg/kg i. p.). Interestingly, this behavioral sensitization was prevented by 8-O H-DPAT (0.35 mg/kg s.c.) prior to stress. Finally, haloperidol-induced sedation was not disrupted by either restraint stress or 8-OH-DPAT tr eatment.