Abstract
The present study investigated whether the anxiolytic effect of 5-HT1A receptor agonists on the fear-potentiated startle response could be antagonized by 5-HT1A receptor antagonists. Therefore, control and fear-potentiated startle amplitudes were measured after co-administration of vehicle, flesinoxan (10 mg/kg PO) or 8-OH-DPAT (0.3 mg/kg SC) and DU 125,530 (0, 1, 3 and 10 mg/kg SC), (±)-pindolol (0, 3, 10 and 30 mg/kg SC) or WAY 100,635 (0, 0.1, 0.3 and 1 mg/kg SC). Unexpectedly, the three antagonists themselves as measured in the vehicle-pretreatment groups dose-dependently decreased startle potentiation. Further, DU 125,530 and WAY 100,635 were able to reverse the attenuating effect of 8-OH-DPAT, while no antagonism of the flesinoxan effect on startle potentiation was found. In contrast, both the flesinoxan- and 8-OH-DPAT-induced lower lip retraction were antagonized by DU 125,530 and WAY 100,635, but not by (±)-pindolol. The findings of the present study suggest that drugs acting on 5-HT1A receptors differentially affect lower lip retraction and startle potentiation probably mediated by different neuronal populations.
Similar content being viewed by others
Author information
Authors and Affiliations
Additional information
Received: 2 October 1997 / Final version: 23 January 1998
Rights and permissions
About this article
Cite this article
Joordens, R., Hijzen, T. & Olivier, B. The effects of 5-HT1A receptor agonists, 5-HT1A receptor antagonists and their interaction on the fear-potentiated startle response. Psychopharmacology 139, 383–390 (1998). https://doi.org/10.1007/s002130050729
Issue Date:
DOI: https://doi.org/10.1007/s002130050729