Spectral and intensity coding in the auditory midbrain

Abstract

This overview emphasizes general properties of spectral and intensity processing in the inferior colliculus (IC) common to mammals such as the cat, mouse, rat, guinea pig, Mongolian gerbil, chinchilla, rhesus monkey, and various species of bats. Considerable data are available for the domestic cat (Felis catus) and mice (Mus musculus, laboratory strains) so that these species can serve as representative unless specified otherwise (for special spectral processing regimens in bats see Chapters 14 and 17). Functional distinctions exist among IC subdivisions (Aitkin 1986). Accordingly, we employ a basic anatomical framework of three major divisions: the central nucleus (ICC), the external nucleus (EN), and the dorsal cortex (DC). In this framework, the ICC contains layer IV of the DC as defined in Golgi studies of the cat (Morest and Oliver 1984) and mouse (Meininger et al. 1986).