Neurochemical organization of the medial geniculate body and auditory cortex

Abstract

The auditory, visual, and somatic sensory systems each have a topographic receptor epithelium, multiple central representations of the peripheral mosaic, parallel neural streams serving epicritic processing, vast networks of central connectivity, and a web of intrinsic circuits at all levels of processing. Marked neurochemical differences distinguish the central auditory system from its visual and somatic sensory counterparts, which each largely conserves the parallel contribution from specific classes of retinal, cutaneous, or neuromuscular receptors; moreover, sight and touch have, relative to audition, fewer synapses in the ascending pathways to neocortex (Dykes 1983; Stone 1983). Perhaps the auditory system has more opportunities for inhibitory and other local interactions.