Influence of ascending noradrenergic fibers on the neurotensin-like immunoreactive neurons in the rat paraventricular nucleus.
Regulation of the neurotensin (NT)-producing neurons by ascending catecholamine fibers in the paraventricular nucleus of the rat hypothalamus was examined using fluorescence histochemistry and immunohistochemistry after the destruction of the ascending catecholamine pathway by 6-hydroxydopamine. On the ipsilaterally operated side, the fluorescence of the catecholamine terminals decreased remarkably in the paraventricular nucleus whereas an accumulation of catecholamine fluorescence was observed in the caudal mesencephalon rostral to the locus coeruleus. In addition, the number of neural perikarya with NT-like immunoreactivity was greatly decreased in the paraventricular nucleus on the operated side compared with the intact side as determined by peroxidase-antiperoxidase immunohistochemistry. This decrease in the NT-like immunoreactive neural perikarya may be due to the disappearance of noradrenergic input to the NT-like immunoreactive neurons through axo-somatic or axo-dendritic synapses.
D000320:Adrenergic Fibers / Q000378:metabolism*; D000818:Animals; D001933:Brain Stem / Q000378:metabolism; D004298:Dopamine / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D007124:Immunoenzyme Techniques; D008297:Male; D008636:Mesencephalon / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D009434:Neural Pathways / Q000378:metabolism; D009479:Neuropeptides; D009496:Neurotensin / Q000378:metabolism*; D009638:Norepinephrine / Q000378:metabolism*; D010286:Paraventricular Hypothalamic Nucleus / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains
D009419:Nerve Tissue Proteins; D009479:Neuropeptides; C031644:neurotensin-like immunoreactivity; D009496:Neurotensin; D004298:Dopamine; D009638:Norepinephrine