Colocalization of urocortin and neuronal nitric oxide synthase in the hypothalamus and Edinger‐Westphal nucleus of the rat

Abstract

Different lines of studies suggest that both the corticotropin-releasing hormone-related peptide Urocortin I (Ucn) and the neuromodulator nitric oxide (NO) are involved in the regulation of the complex mechanisms controlling feeding and anxiety-related behaviors. The aim of the present study was to investigate the possible interaction between Ucn and NO in the hypothalamic paraventricular nucleus (PVN), an area known to be involved in the modulation of these particular behaviors. Therefore, we mapped local mRNA and peptide/protein presence of both Ucn and the NO producing neuronal NO synthase (nNOS). This investigation was extended to include the hypothalamic supraoptic nucleus (SON) and the Edinger-Westphal nucleus area (EW), the latter being one of the major cellular Ucn-expressing sites. Furthermore, we compared the two predominantly used laboratory rat strains, Wistar and Sprague-Dawley. Ucn mRNA and immunoreactivity were detected in the SON and in the EW. A significant difference between Wistar and Sprague-Dawley rats was found in mRNA levels in the EW. nNOS was detected in all brain areas analyzed, showing a significantly lower immunoreactivity in the PVN and EW of Sprague-Dawley versus Wistar rats. Contrary to some previous reports, no Ucn mRNA and only a very low immunoreactivity were detectable in the PVN of either rat strain. Interestingly, double-labeling immunofluorescence revealed that in the SON approximately 75% of all cells immunoreactive for Ucn were colocalized with nNOS, whereas in the EW only approximately 2% of the Ucn neurons were found to contain nNOS. These findings suggest an interaction between Ucn and NO signaling within the SON, rather than the PVN, that may modulate the regulation of feeding, reproduction, and anxiety-related behaviors.

Distribution of NADPH-diaphorase and nitric oxide synthase reactivity in the central nervous system of the goldfish (Carassius auratus)

“…These latter data are in disagreement with the previous study in goldfish (Brüning et al, 1995). In land vertebrates, labeling in these latter nuclei remains controversial: some studies report positive labeling (Mizukawa et al, 1989;Bennis et al, 1996;Spina et al, 2004), but not others . These nuclei are involved in the motor control of eye and body movements (Pastor et al, 1991;Fetcho and Svoboda, 1993).…”

Neuroanatomical localization of nitric oxide synthase (nNOS) in the central nervous system of carp,Labeo rohitaduring post‐embryonic development

“…Although, Villani (1999) did not report the presence of nitrergic cells in Nmlf during the early development of Tilapia mariae but the presence of nitrergic cells in Nmlf of fishes had been reported by different investigators (Jadhao and Malz, 2004;Giraldez-Perez et al, 2008). Nitrergic cells in nIII had also been reported in other vertebrate species (Bennis et al, 1996;Mizukawa et al, 1989;Spina et al, 2004). The nIII is thought to be associated with motor control of the eyes and several body movements (Pastor et al, 1991).…”

Stress and the Reproductive System

“…They have moderate 5. 31,32 In contrast, UCN2 is highly expressed in the PVN, supraoptic nucleus, BNST, and locus ceruleus 33 and UNC3 is highly expressed in the PVN, BNST, medial preoptic area, and medial amygdala nucleus 34,35 ; sites critical not only for stress activation but also control of the reproductive axis. 30 UCN1 is highly expressed in the Edinger-Westphal nucleus and supraoptic nucleus, but very low levels are seen in the PVN.…”