Volume 11 Issue 3, March 2008

Calcium is a ubiquitous second messenger in the nervous system linking extracellular and intracellular events. Now a study identifies it as a primary messenger controlling axon and dendrite outgrowth during development via activation of extracellular calcium-sensing receptors, better known in the liver and thyroid than in the brain.

Motor neurons and muscle fibers interact in complex ways to build the neuromuscular synapse. A new study shows that β-catenin is required in muscle to provide an unknown retrograde signal that is necessary for presynaptic transmitter release.

Descending projection neurons to the spinal cord carry important information for movement initiation and control. A new study shows that relatively few projection neurons may be needed to generate certain visually guided movements.

Even well-practiced skills show trial-by-trial variations. A study in Nature suggests that such variability may be adaptive, allowing for plasticity in apparently crystallized skills, which should therefore be considered more like templates.