Effect of Induced Hypertension on Bilateral Activity, Task Performance and Spatial Memory In Albino Wistar Rat

¹Olorunfemi O.J.^*, ²Okosiemiama S.C., ³Okopido I.S, ⁴Okpe E.
Department of Human Physiology, Faculty of Basic Medical Sciences, College of Health Sciences, University of Port Harcourt, Choba, Port Harcourt, Nigeria.

A B S T R A C T
The aim of this study is to evaluate the possible effect of induced hypertension on bilateral activity, task performance and spatial memory. Twenty albino wistar rats weighing between 100 and 230g were randomly divided into four (4) groups. The control group (group I) received only feed and water while the experimental group II were administered 6ml of dietary salt orally at 2ml each day for (3) days to induce hypertension and later treated with 1.6 ml methyldopa administered orally at 0.2ml for (8) days, group III were administered a total of 0.4ml atropine intraperitoneally to induce hypertension. Group IV were administered 0.4ml orally and 0.6ml amlodipine intraperitoneally to induce low blood pressure. The rats were released for task performance tests in inverted screen test, navigational maze, beam walk and hand grip. Spatial memory test was also carried out by recognition of novel objects in space as well as bilateral activity test. Results obtained from navigational maze test revealed that salt-induced hypertension significantly (P˂0.05) enhanced navigation task performance in albino wistar rats. Results from inverted screen and hand grip test showed that induced-hypertension and low blood pressure significantly (P˂0.05) impaired the motor functions in task performance of rats in inverted screen, beam walk and hand grip test. Results obtained from bilateral activity test indicated that the control group skewed equal attention to both clockwise and anti-clockwise direction. Thus induced hypertension and amlodipine-induced low blood pressure significantly (P˂0.05) impaired the performance of rats in bilateral activity test. From the cognitive function (spatial memory) object recognition test, induced hypertension and amlodipine-induced low blood pressure significantly (P˂0.05) enhanced spatial memory of rats in the cognition test.
Keywords: spatial memory, bilateral activity, methyldopa, amlodipine, navigational maze, beam walk and hand grip.