Abstract
Summary
1. Electron microscope studies of a type of physiologically polarized synapse in the crayfish and the squid have shown that the synapse consists of a region characterized by processes of postsynaptic axoplasm lying in presynaptic Schwann cell cytoplasm. 2. The axolemmal membrane of the postsynaptic fiber completely envelops the synaptic processes and is closely applied to the corresponding axolemmal membrane of the presynaptic fiber in a manner such that a single membrane of double thickness is sometimes produced. 3. Pre- and postsynaptic axolemmal membranes are structurally similar and are about 300 Â in thickness. 4. The axoplasm of the postsynaptic fiber and of the synaptic processes contains a distinctly increased number of axoplasmic filaments per unit volume over that of presynaptic axoplasm.
Get full access to this article
View all access options for this article.