Single restraint stress sensitizes acute chewing movements induced by haloperidol, but not if the 5-HT agonist 8-OH-DPAT is given prior to stress

Abstract

The objective of this study was two-fold: ( i) to analyze behavioral sensitization to haloperidol 2 weeks after single restraint stress, and ( ii) to establish the effects of 8-OH-DPAT treatment prior to stress on sensitized behavioral responses. Overall behavior was analyzed and not only catalepsy, but also sedation immobility, grooming, exploration and vacuous chewing movements were evaluated. Results indicated that single restraint stress induced a long-lasting sensitization of acute vacuous chewing movements induced by haloperidol (0.25, 0.5 mgrkg i.p) Interestingly, this behavioral sensitization was prevented by 8-OH-DPAT (0.35 mgrkg s.c.) prior to stress. Finally, haloperidol-induced sedation was not disrupted by either restraint stress or 8-OH-DPAT treatment.