| The morphological and physiological features of a putative connection between the main and accessory olfactory bulbs and the supraoptic (SON) and paraventricular nuclei (PVN) of the rat were studied using a combination of anatomical and electrophysiological techniques. Neurophysin immunocytochemistry revealed the supraoptic nucleus dendritic plexus which coursed anteroposteriorly ventral to supraoptic somata. Additionally, a portion of this plexus also projected ventrolaterally into periamygdaloid areas, a feature of supraoptic nucleus architecture which is not generally appreciated. Injections of the anterogradely transported substances, wheatgerm agglutinin conjugated horseradish peroxidase (WGA-HRP) or Phaseolus vulgaris leucoagglutinin into the main accessory bulb and injections of WGA-HRP into the accessory bulb revealed a dense plexus of terminals and fibers ventrolateral to the ipsilatreral supraoptic nucleus. The pattern of anterogradely labeled fibers and terminals appeared to overlap with the distribution of ventrolaterally projecting neurophysin-containing processes. Since the latter consists of dendritic processes of supraoptic origin, this suggests that both olfactory bulbs project to the SON. No labeled fibers appeared near the PVN. Injections of rhodamine-labeled latex microspheres or Fluoro-Gold... |
