In vivo synaptic recovery following optogenetic hyperstimulation

Chemical synapses are key contact points in the nervous system, where signals are transmitted between neurons. These signals, small chemical molecules, are released from membranous synaptic vesicles by fusion with the neuronal membrane. Synaptic vesicle membrane and proteins need to be recycled to support ongoing transmission. Upon seizure, massive amounts of synaptic vesicles fuse, while neurons become exhausted and need to recover. We used optical stimulation of neurons in live Caenorhabditis elegans nematodes to induce extreme neuronal activity and followed processes underlying the recovery progression at behavioral, genetic, physiological, and ultrastructural levels in an intact animal.