An Immunohistochemical Study of the Pathways of the Influence of Dopamine on Orexinergic Neurons in the Perifornical Area of the Hypothalamus
- 2 Downloads
Confocal microscopy was used to analyze double immunolabeling and provided evidence of the locations of a large number of tyrosine hydroxylase-immunopositive processes around the bodies of orexinergic neurons located in the perifornical area of the hypothalamus in rats. The bodies of orexinergic neurons were found to bear dopamine D1 receptors. A high level of colocalization of dopamine D1 and D2 receptors was found in the perifornical area, which is evidence for the formation of heterodimeric D1/D2 complexes. After i.p. administration of the selective D1 receptor antagonist SCH 39166, neurons in the perifornical area showed increases in the optical density of c-Fos protein in both orexinergic neurons and their adjacent GABA neurons. These data provide evidence that dopamine is able to influence orexinergic neurons both via a direct route involving D1- and D2-dependent signal pathways and via influences on GABA neurons.
Keywordsbrain orexins hypothalamus dopamine dopamine D1 and D2 receptors GABA
Unable to display preview. Download preview PDF.
- 1.I. Yu. Morina and A. L. Mikhrina, “Involvement of catecholamines in the regulation of orexinergic neurons in the mammalian brain,” Med. Akad. Zh., 17, No. 4, (2017).Google Scholar
- 2.I. V. Romanova, “Morphofunctional interaction of CART peptide and dopaminergic neurons in the brain,” Zh. Evolyuts. Biokhim. Fiziol., 49, No. 1, 78–84 (2013).Google Scholar
- 3.I. V. Romanova, A. L. Mikhrina, and A. O. Shpakov, “Localization of types 1 and 2 dopamine receptors on the bodies of COMT-expressing neurons of the arcuate nucleus of the hypothalamus in mice and rats,” Dokl. Akad. Nauk., 472, No. 5, 608–611 (2017).Google Scholar
- 4.I. V. Romanova, A. L. Mikhrina, and A. O. Shpakov, “Immunohistochemical evidence for the localization of dopamine receptors on neuropeptide Y-expressing neurons in the rat arcuate nuclei,” Zh. Evolyuts. Biokhim. Fiziol., 54, No. 3, 220–222 (2018).Google Scholar
- 5.M. V. Ugryumov, Mechanisms of Neuroendocrine Regulation, Nauka, Moscow (1999).Google Scholar
- 12.G. Paxinos and C. Watson, The Rat Brain in Stereotaxic Coordinates, Academic Press, San Diego (1998), 4th ed., ISBN 0-12-547617-5.Google Scholar