Agrin drives synaptogenesis

The nerve-derived growth factor agrin is now shown by Martin et al. (page 503) to turn broadcast communication into personalized messaging.Agrin is well-established as a differentiation and maturation factor at the neuromuscular junction: it helps form the connections between nerves and muscles by inducing aggregation of acetylcholine receptors on muscle cells. Now, Martin et al. demonstrate that agrin also promotes synaptogenesis between two neurons. The protein shuts off gap junction-mediated communication between cells while stimulating maturation of the nicotinic synapses.

Agrin is widely expressed in neural tissue, including the adrenal gland, but its function there wasn't clear. Meanwhile, intercellular connections between chromaffin cells in the developing adrenal medulla shift during the first week after birth from electrically modulated communication using gap junctions to synaptic communication that is chemically based. The factors that control that...