Effects of midbrain reticular lesions upon the orienting response in the rat.

Abstract
30 male hooded rats with bilateral lesions in the midbrain reticular formation (MRF) showed no differences in the acquisition and extinction of a runway response in comparison to sham-operated controls. However, Ss with MRF lesions showed a significant decrease in the duration of an orienting response (exploratory behavior) to a novel stimulus and showed no recovery of the orienting response the next day. No differences were found in rate of habituation to the novel stimulus. (PsycINFO Database Record (c) 2006 APA, all rights reserved)