Functional reorganization of neural auditory maps by differential learning.

A new perspective on neural mechanisms of learning is emerging from studies showing that some sensory maps in mature brains can be reorganized in response to conditioned stimuli. Autoradiography with [14C] 2-deoxy-2-fluoro-D-glucose was used to examine changes in the functional tonotopic organization of the rat inferior colliculus during differential Pavlovian conditioning. Metabolic comparisons of adjacent tonotopic maps were made within the same inferior colliculus. They showed that tonotopic maps were enhanced during differential learning of tones associated with an arousing stimulus. The findings support a concept of sensory learning that postulates a functional reorganization of sensory maps in adult brains.