Experience-Dependent Response Plasticity in the Auditory Cortex: Issues, Characteristics, Mechanisms, and Functions

The goal of this chapter is to provide a guide for understanding experience-dependent neuronal plasticity in the auditory cortex and its relation to behavior. (Unless otherwise noted, “auditory cortex” refers to the tonotopic primary auditory field, AI). It focuses on research that began in the mid-1980s concerning the question of how learning may alter the processing and representation of acoustic information in the primary auditory cortex. As used here, the term “plasticity” refers to systematic long-term (minutes to months) changes in the responses of neurons to sound as a result of experience. Plasticity at the level of altered neural responses is the result of various subcellular and molecular processes. Selected aspects of these substrates are included, particularly those relating to the cholinergic modulation of auditory cortical plasticity. Owing to lack of space, the subcortical auditory system cannot be reviewed, except as it directly pertains to mechanisms of cortical plasticity (see Birt et al. 1979; Cruickshank et al. 1992; Edeline and Weinberger 1992; Gonzalez-Lima and Scheich 1992; Hennevin et al. 1993; McKernan and Shinnick-Gallagher 1997).