The ventricular system in neuroendocrine mechanisms. III. Supraependymal neuronal networks in the primate brain.

This investigation has utilized a correlative scanning-transmission electron microscopic technique in the analysis of the primate cerebral ventricular system. This approach has demonstrated a complex network of supraependymal cellular elements upon the walls of the third cerebral ventricle in direct contact with the ventricular lumen. Type I neuronal-like cells and type II histiocytic-like cells with potential phagocytic capabilities have been observed in large numbers throughout the third ventricle. Type I neuron-like cells are discussed in the context that they may represent a population of receptor-cells which serve to assess ambient changes in the composition of bioactive peptides in the cerebrospinal fluid and may serve as a supraependymal network that integrates the endocrine hypothalamus with other circumventricular organs which may also be sites of neuroendocrine transduction.