Glia keep synapse distribution under wraps

Abstract

The wiring of the nervous system requires that axons navigate to the correct targets and maintain their correct positions during developmental growth. In this issue, Shao et al. (2013) now reveal a crucial new role for glia in preserving correct synaptic connectivity during developmental growth.

Figure 1. Glial Processes Maintain Presynaptic Site Distribution during Growth

(A) In wild-type animals, an SLC17 transporter CIMA-1 negatively regulates EGL-15(5A) expression, by an unknown mechanism, to reduce epidermalglia adhesion and prevent glial endfoot extension during growth. This interaction maintains the glial cell morphology, which in turn preserves the correct presynaptic site distribution during growth. (B) In animals with cima-1 loss-of-function mutations, or in animals in which egl-15(5A) is overexpressed, the interaction between the epidermal cells and the glia is misregulated. This results in the inappropriate extension of the glial endfeet, and the formation of ectopic presynaptic sites.