A previous report revealed that bilateral injury to the mamillary bodies, mamillothalamic tract, or anterior thalamus significantly interfered with the rat's ability to perform position reversals on a T maze. The current study endeavored to show whether lesions involving other anatomically related structures would have similar effects on the reversal task. Bilateral damage to the hippocampus, precallosal limbic area, septum, lateral preoptic hypothalamus, or the substantia nigra significantly disturbed reversal performance. However, destruction of the supracallosal limbic area, post-commissural fornix, posterior thalamus, habenular complex, laberal subthalamus, amygdala, or the dorsolateral surface of the cerebral cortex failed to produce any significant effects. (21 ref.) (PsycINFO Database Record (c) 2006 APA, all rights reserved)