HYPOTHALAMIC DISTRIBUTION OF STRIA TERMINALIS IN RAT

The hypothalamic distribution of the stria terminalis was studied by the Fink-Heimer methods and electron microscopy in rats sacrificed 3-6 days after unilateral amygdalectomy or stria terminalis section. Each of the major hypothalamic stria components was found to be distributed to fairly sharply defined regions, as follows: (1) The postcommissural component terminals massively in the rostral half of the anterior hypothalamic nucleus; an apparently small number of its fibers join the medial forebrain bundle. (2) The supracommissural component terminates predominantly in a dense synaptic zone surrounding the ventromedial nucleus and containing a massive plexus dendrites protruding from this nucleus, in smaller quantity also in lateral and ventral parts of the ventromedial nucleus proper and in the ventral premammillary nucleus. The prevalence in the hypothalamus of neurons with long dendrites suggests that the stria terminalis may have synaptic contracts not only with perikarya and dendrites of neurons lying within its synaptic fields, but also with dendrites of neurons whose cell bodies lie well outside these fields. © 1969.