Excitatory and inhibitory synaptic placement and functional implications

Abstract

Synaptic transmission between neurons is the basic unit of communication in neural circuits. The relative number and distribution of excitatory and inhibitory synaptic inputs across individual dendrites and neurons are the hardware of local dendritic and cellular computations. In this chapter, we discuss the structural and functional observations that have guided the understanding of excitatory and inhibitory synaptic organization across the neuronal arbor, the subcellular targeting properties of different neuronal subtypes, and the effects of synaptic placement on local integration within dendritic segments. We focus primarily on the adult mammalian cortex and hippocampus, where excitatory and inhibitory cell types, their connectivity, and its functional implications have been best characterized.