Evidence for the existence of an enkephalin-containing pathway from the area just ventrolateral to the anterior hypothalamic nucleus to the lateral septal area of the rat.

The afferent source of enkephalin-like immunoreactive (ELI) fibers in the lateral septal area of the rat was elucidated experimentally by means of an indirect immunofluorescence technique. These ELI fibers had almost completely disappeared on the operated side after the destruction of the area just ventrolateral to the anterior hypothalamic nucleus, where a number of ELI cells was detected. This fact strongly suggests that these ELI cells project ipsilaterally to the lateral septal area.