Enhanced visuomotor associative learning following stimulation of α 2A-adrenoceptors in the ventral prefrontal cortex in monkeys

Abstract

The present study investigated the effect of locally infused guanfacine, an α 2A-adrenergic agonist, into the ventral prefrontal cortex (PFv) on visuomotor associative learning. Two monkeys were well trained on a two-problem visuomotor associative task: the monkeys performed movement A if presented with a circle pattern, or movement B if presented with a triangle pattern. For learning of new visuomotor associations, the monkeys were presented with a new set of four patterns in each and every daily session, two of which instructed movement A and the other two movement B. Bilaterally infused guanfacine (2.5 μg/μl; 3 μl on each side) improved the monkeys' ability to learn new visuomotor associations: trials and errors to learning criterion of 90% correct decreased significantly. The monkeys showed an enhanced capability to use win–stay/lose–shift strategy on ‘repeat trials’ and change–stay/ change–shift strategy on ‘change trials.’ The present results indicate that α 2A-adrenoceptor in the PFv is involved in regulating visuomotor associative learning.