A substance P-containing pathway from the hypothalamic ventromedial nucleus to the medial preoptic area of the rat: an immunohistochemical analysis.
The destruction of the hypothalamic ventromedial nucleus, which contains a group of substance P-like immunoreactive neurons, resulted in a marked ipsilateral reduction of these fibers in the medial preoptic area. To test if and to what extent the substance P-like immunoreactive neurons in the ventromedial nucleus project to the medial preoptic area, we applied a sensitive double-labeling method capable of detecting substance P-like immunoreactivity in neurons retrogradely labeled with biotin-wheat germ agglutinin following injection of the tracer in the medial preoptic area. The appearance of many double-labeled cells in the hypothalamic ventromedial nucleus provides strong evidence for the existence of a prominent substance P containing pathway from the ventromedial nucleus to the medial preoptic area. A few doubled-labeled cells were also seen in the lateral hypothalamus, which therefore seems to be an additional source of substance P-like immunoreactive fibers in the medial preoptic area.
D000818:Animals; D008297:Male; D009434:Neural Pathways / Q000033:anatomy & histology / Q000378:metabolism; D010455:Peptides / Q000378:metabolism; D011301:Preoptic Area / Q000033:anatomy & histology / Q000378:metabolism*; D051381:Rats; D013373:Substance P / Q000378:metabolism*; D014697:Ventromedial Hypothalamic Nucleus / Q000033:anatomy & histology / Q000378:metabolism*
D010455:Peptides; D013373:Substance P