Neurobehavioral evaluation of high blood pressure and low blood pressure mice

Abstract

Mice chronically subjected to high blood pressure (HBP) or to low blood pressure (LBP) were compared with normotensive controls in tests of exploration, motor coordination, and spatial learning at two age levels: young adult (3 months) and middle-aged (12 months). At either age, by comparison with controls, HBP mice were hyperactive in an open field, but not in terms of hole-poking responses. On the contrary, LBP mice were hypoactive in the open field and in the hole board, with the effect on the former measure being limited to the younger cohort. In either cohort, HBP and LBP mice were deficient in some aspects of sensorimotor testing requiring balance and equilibrium. Moreover, HBP and LBP mice had longer path lengths and escape latencies during acquisition of a hidden platform in a water maze. In the younger cohort, LBP mice had longer path lengths and escape latencies, even during a visible platform version of the task, an indication of a disturbed visuomotor function. These mutants may serve as experimental models for the evaluation of beneficial antihypertensive or antihypotensive treatments on brain function.