The effects of subdural haematoma on spatial learning in the rat

Although memory deficits are one of the most persistent consequences of hum an subdural haematoma, cognitive functioning has hardly been investigated i n the rat subdural haematoma model. In the present study, the effects on sp atial learning of right- and left-sided unilateral subdural haematoma and o f bilateral subdural haematoma induced above the sensorimotor cortical area s were evaluated. Spatial learning was assessed by standard acquisition in the Morris water escape task (five sessions). Additional issues addressed w ere sensorimotor functioning (footprint analysis), recovery of cognitive fu nctioning (tested by an overtraining and a reversal training) and replicabi lity of induced cognitive deficits. Following unilateral subdural haematoma surgery, hardly any impairments in the Morris water escape task were obser ved: rats with a unilateral right-sided subdural haematoma showed very mild , transient deficits, whereas rats with left-sided subdural haematoma were indistinguishable from controls. Bilateral subdural haematoma surgery led t o a clear, although transient, performance deficit. We conclude that animals with bilateral subdural haematoma may provide a pr omising cognitive deficit model for investigating recovery of function. (C) 1999 IBRO. Published by Elsevier Science Ltd.