MECHANISMS REGULATING BOTH SMALL- AND LARGE-SCALE AXON PRUNING WITHIN VISUAL CORTICAL EFFERENT CELLS

Axon pruning is generally divided into two categories based on relative scale: 1) small-scale axon terminal pruning within a localized target area, and 2) large-scale stereotyped pruning of long axon collaterals from multiple target areas. Prior studies have independently examined regulatory mechanisms for neurons undergoing either small- or large-scale pruning. My laboratory is the first to examine molecular and neural activity mechanisms regulating both small- and large-scale axon pruning within the same cell.

Approach: Visual cortex layer 5 pyramidal neurons undergo both small-scale pruning of axon terminals in the pons and large-scale stereotyped pruning of transient corticospinal tract axons. Using molecular genetics and pharmacological techniques to examine this cell population, we are determining whether both types of axon pruning are regulated by the same set of mechanisms or differentially regulated within the same cells.

Impact: Comprehensive understanding of regulatory mechanisms underlying axon pruning during development in wild-type and disease models will enable development of earlier prognosis, improvement of current therapeutic treatments for patients, and potentially novel therapeutic targets for medicinal drug development.