Ultrastructural immunocytochemical localization of neurophysin in freeze-substituted neurohypophysis.

Using an immunohistochemical technique at the electron microscopic level, we have observed that within the axon terminals of the guinea pig neurohypophysis neurophysin is present in the large neurosecretory granules, as well as in the axoplasm. A description of a freeze-substitution technique for neural lobe is also present.