DIFFERENTIAL BEHAVIORAL-EFFECTS OF ANGIOTENSIN-II MICROINJECTED UNILATERALLY INTO THE CA1 HIPPOCAMPAL AREA

The behavioral responses of rats to unilateral microinjections of angi otensin II (ATII) into the left or right CA1 hippocampal area were stu died. Unilateral (left or right) injections of ATII at a dose of 0.5 m u g decreased locomotor activity but, at a dose of 1.0 mu g, ATII incr eased it compared to the respective controls. The effect was more pron ounced when ATII was microinjected into the left CA1 hippocampal area. The elevated plus-maze experiments showed that ATII microinjections i nto the right CA1 hippocampal area at a dose of 0.5 mu g decreased the ratio of the number of entries into the open arms to the total number of entries (into the open and closed arms). These findings suggest so me asymmetric effects of ATII, depending on the dose, the behavioral t est and the microinjected hemisphere. (C) 1998 Elsevier Science B.V.