Some Functional Properties of the Somatic Afferent System

Abstract This chapter aims to pursue two general themes. The first is that it is necessary to look to something more than anatomical connections between a given sensory sheet and the neural centers upon which it projects to understand the very highly developed capacities for discrimination that mammalian afferent systems possess. A description is presented here of some of the dynamic attributes of the somatic afferent system that contribute to its discriminative capacity, with particular emphasis on the role of afferent inhibition in its function. The second theme is concerned with describing the functional properties of some of the neural elements of this system, observed at thalamic and cortical levels. This system is referred to in terms of a set of properties than as an anatomical entity, and the terms posterior group or spinothalamic are used loosely here.