NEUROETHOLOGICAL ANALYSIS OF WISTAR RATS INJECTED I.C.V. WITH VENOM AND ISOLATED FRACTIONS OF THE SOCIAL WASP Agelaia vicina

Oliveira, L., Ribeiro, A.M., Pizzo, A.B., Guizzo, R., Miranda, A., Santos, W.F.

Neurobiology and Venoms Laboratory, FFCLRP, USP and Biophysics Department, UNIFESP, SP. 

Objectives: To evaluate the behavioral effects caused by i.c.v. injection in rats, of the venom from the social wasp Agelaia vicina and the fractions isolated by reverse phase HPLC in Wistar rats. Materials and methods: Cannules were implanted in the lateral ventricle of male Wistar rats (200-250g), using stereotaxic determined coordinates. Animal behavior was registered in VHS tapes for 30 min. in intervals of 180 sec 5, 10 and 15 min after injection. The rats (n=6) were injected with 3 mL of denatured venom (15,30 and 60 glands) and with crude venom (30 glands). To analyze the animals’ behavior open field, rotarod and bar models were used. Results: The rats (n=6) had their locomotor activity reduced after intracerebroventricular injection (90%). This could be seen as a significant decrease of the number of line crossings in the open field. The animals treated with 60 glands did not equilibrate on the Rotarod (100%) in the periods of 5, 10, 20 and 30 min after injection demonstrating an ataxic frame. In suspended bar experiments rats injected with haloperidol and 60 glands were able to stay stained in the periods of 5 and 30 min indicating catalepsy (83%) .The injection of 3mL from the fractions (AvTx 1-4) purified by HPLC reverse-phase in acetonitrile/water/TFA gradient also reduced significantly the animal’s locomotor activity as well as the number of line crossings (85%). Concluding, the venom of A. vicina and the fractions purified by HPLC may contain components that could be helpful in understanding the neurotransmission system involved in locomotor activity, catalepsy and ataxia.

Financial support: CAPES, CNPq and FAPESP

CORRESPONDENCE TO:

Luciana de Oliveira, Rua Liberdade 171, Ribeirão Preto, SP, CEP: 14085250, Brasil, Email: luoli@usp.br