Activity and Competition-Dependent Synapse Repression in Culture

Abstract

Throughout the nervous system neurons receive many more synaptic inputs prior to birth than are retained into adulthood¹. Regulators of this rearrangement are poorly understood, but seem to include an element of competition between inputs for particular domains of space on a postsynaptic cell. The competition depends in part upon the amount of neuronal activity or its patterning, and in part upon ill-defined components of the pre- and postsynaptic cells that make some connections “appropriate” and some foreign, or “inappropriate”. Were such rearrangements to occur in cell culture systems they might be more accessible to cellular, biochemical, and molecular genetic characterization. In the restricted environment of cell culture many options for the cells are better controlled, especially when homogeneous populations are used, and electrophysiological access for assay of synapse formation is straightforward. Synapse plasticity can be examined when manipulating the cellular and soluble constituents as well as the degree of neuronal activity.