ABERRANT NEURITES AND SYNAPTIC VESICLE PROTEIN-DEFICIENCY IN SYNAPSINII-DEPLETED NEURONS

Synapsin I and synapsin II are neuron-specific phosphoproteins that ha ve a role in the regulation of neurotransmitter release and in the for mation of nerve terminals. After depletion of synapsin II by antisense oligonucleotides, rat hippocampal neurons in culture were unable to c onsolidate their minor processes and did not elongate axons. These abe rrant morphological changes were accompanied by an abnormal distributi on of intracellular filamentous actin (F-actin). In addition, synapsin II suppression resulted in a selective decrease in the amounts of sev eral synaptic vesicle-associated proteins. These data suggest that syn apsin II participates in cytoskeletal organization during the early st ages of nerve cell development.