title: The localization of projection neurons in the rat hypothalamic paraventricular nucleus following vascular and neurohypophysial injections of HRP.
abstract: Projection neurons in the rat hypothalamic paraventricular nucleus (pv) were identified using the retrograde transport of horseradish peroxidase (HRP) following injections of this tracer into the neurohypophysis or jugular vein. The objective was to determine if parvocellular pv neurons might be labelled by either injection in addition to the well known magnocellular contingent. Injections confined to the neurohypophysis resulted in the labelling of only magnocellular pv neurons, while intrajugular injections which produced spread of the HRP to the arcuate nucleus-median eminence region resulted in the labelling of both parvocellular and magnocellular pv elements. Thus parvocellular pv neurons may project to the arcuate nucleus and/or the external layer of the median eminance but not to the neurohypophysis.
mesh_terms: D000818:Animals; D001370:Axonal Transport; D001812:Blood-Brain Barrier; D006735:Horseradish Peroxidase; D007031:Hypothalamus / Q000033:anatomy & histology*; D007275:Injections, Intravenous; D008297:Male; D008473:Median Eminence / Q000033:anatomy & histology; D009474:Neurons / Q000648:ultrastructure; D010286:Paraventricular Hypothalamic Nucleus / Q000033:anatomy & histology*; D010904:Pituitary Gland, Posterior / Q000033:anatomy & histology; D051381:Rats
chemical_list: D006735:Horseradish Peroxidase