Behaviour of the genetically hypertensive rats of Koletsky type in holeboard and in elevated plus-maze: effect of scopolamine and nicergoline treatment.

The experiments were performed in the adult normotensive rats of Wistar strain and in the genetically hypertensive rats which were developed by Koletsky (12); both sexes were used. The behavior in control and in Scopolamine and Nicergoline treated rats was traced in the holeboard and in the elevated plus-maze. In the control animals, when compared to the normotensive rats of Wistar strain, the genetically hypertensive rats of both sexes show elevated aversion towards open space and hight in the elevated plus-maze, reduced time spent head dipping in holeboard, reduced rate of habituation of locomotor-exploratory activity, and the elevated total time of locomotor-exploratory activity in holeboard. Scopolamine at dose 0.25 mg/kg b. w. and Nicergoline at dose 4 mg/kg b. w. reduced the aversion towards the open space and hight in elevated plus-maze only in the genetically hypertensive rats of both sexes. Both drug when applied simultaneously show mutual potentiation in the genetically hypertensive rats. Both drugs when applied separately or simultaneously caused elevation of time spent head dipping, i. e., elevation of directed exploration. Nicergoline caused decrease and Scopolamine caused increase of total time of exploratory activity in holeboard. Nicergoline increases the rate of habituation of the locomotor-exploratory activity in the males of normotensive rats and in the genetically hypertensive rats of both sexes. Scopolamine remained without effect in the normotensive rats of both sexes, elevated the rate of habituation in the genetically hypertensive males.