An unconventional role of neurotransmission in synapse formation

How do presynatic inputs regulate synapse formation? In this issue of Neuron, Lin et al. show that the neurotransmitter acetylcholine decreases the stability of AChR clusters. This dispersing activity, which requires the serine/threonine kinase Cdk5, cooperates with positive signals from motoneurons to ensure high concentration of AChRs at the neuromuscular junction.