Ultrastructural analysis of the posterior hypothalamus of salamander

The anatomical organization of the tuberal area of th posterior hypothalamus in Salamandra was investigated by the Golgi methods, SEM and TEM techniques. The ependymal cells of this area are poor in cilia and often show morphological features of actively secreting or absorbing elements. Intermingled with ependymal cells, two kinds of CSF-contacting processes are seen, arising from neurons of the periventricular grey. Their contents and morphological characteristics allow them to be divided into two groups, A and B. In the neuropil different synaptic contacts are seen. The observation of unconventional synaptic contacts possibly of axo-axonic type suggests the occurrence of local circuits on the final neurosecretory pathway.