Incorporation of radioactive methionine into giant neurons of the mollusk

In the buccal ganglia of the freshwater mollusk Planorbis co~'neus protein synthesis takes place most intensively in thebodies of nerve cells. Protein synthesis in giant neurons takes place with equal intensity both in cytoplasm and nucleus, 60% of the total mass of sulfur-containin g protein being produced by the cytoplasm. Protein leaves the neuron body principally along the axon. It migrates along the axon at a rate of about 0.2mm/day. Giant neurons of the buceal ganglia are characterized by very high electrical activity, giving way periodically (at intervals of 3-5 sec) to deep and prolonged (about 1 see) inhibition. This type of periodic unit activity continues substantially unchanged for up to 20 hr if the surrounding isotonic solution is constantly renewed.