Cataleptic activity of the denatured venom of the social wasp Agelaia vicina (Hymenoptera, Vespidae) in Rattus norvegicus (Rodentia, Muridae)

Catalepsy is a state of immobility, commonly experienced by patients with chronic use of many antiparkisonism and neuroleptic drugs. Recently, catatonia has been considered as an evolutionary-based fear response. The cataleptogenic effects of the low molecular weight compounds from the venom of the social wasp A. vicina (AdAv) were reported in rodents. Intracerebroventricular injections of AdAv in highest dose reduced the locomotor activity of Wistar rats in the open field and induced ataxia and catalepsy within 10 min. This effect could be observed up to 30 min after injections. Lower doses of denatured venom injected in brain ventricles also reduced the locomotor activity of the rats but did not induce catalepsy. The cataleptic effects of the intracerebrally administered AdAv were antagonized by the peripheral (intraperitoneal) pretreatment with theophylline and ketamine. Moreover, the central effects of the AdAv were compared to those elicited by the neuroleptic drug haloperidol (intraperitoneally administered), whose cataleptic effects were also antagonized by theophylline and ketamine. However, the association of haloperidol and denatured venom was reverted by theophylline but not by ketamine. These findings suggest that A. vicina venom may affect neural substrates involved with catalepsy in the central nervous system.