....In a study to be published in the journal Nature online March 30, the NYU Langone neuroscientists tracked neuronal activity in dendritic nerve branches as the mice learned motor tasks such as how to run forward and backward on a small treadmill. They concluded that the generation of calcium ion spikes -- which appeared in screen images as tiny "lightning bolts" in these dendrites -- was tied to the strengthening or weakening of connections between neurons, hallmarks of learning new information....