Simple and choice reaction time performance following occlusion of the anterior cerebral arteries in the rat

Focal cerebral ischemia in the rat has traditionally been studied by examining the consequences of middle-cerebral artery occlusion. However, the anterior-cerebral arteries of the rat may now also be bilaterally occluded by stereotaxic injection of the vasoconstrictor endothelin-l, resulting in ischemic damage to medial prefrontal cortex and the anteromedial basal forebrain. The behavioural consequences of anterior-cerebral artery occlusion (ACAo) were studied in two experiments using simple and choice reaction-time tasks designed to dissociate response impairments from dysfunction of motivation and attention, respectively. Following ACAo, reaction-time increased post-surgery in the choice, but not simple reaction-time task. There was also an increase in incorrect choices in the choice reaction-time task. However, the impairments were independent of motivational or attentional function, which remained intact. Although the ACAo-induced ischemic damage did not disrupt motivation or attention, the results suggest that the lesion results in an executive impairment in selecting and initiating responses.