Morphological study of orexin neurons in the hypothalamus of the Long–Evans rat, with special reference to co-expression of orexin and NADPH-diaphorase or nitric oxide synthase activities

Cheng, Shi-Bin; Kuchiiwa, Satoshi; Gao, Hongzhi; Kuchiiwa, Toshiko; Nakagawa, Shiro

doi:10.1016/s0168-0102(03)00026-9

Cited by 37 publications

(30 citation statements)

References 61 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The distribution of nNOS staining has been previously mapped within the hypothalamus (Cheng et al, 2003;Cutler et al, 2001;Yamada et al, 1996). The pattern of staining observed in the present study is in close agreement with these previous reports whereby a large number of nNOS-like immunoreactive neurons were seen among a dense fiber plexus running dorsomedially towards the columns of the fornix.…”

Section: Discussionsupporting

confidence: 93%

“…More recently, however, Cutler et al (2001) specifically investigated the incidence of colocalization between orexin-A and nNOS within the hypothalamus. Orexins (also termed hypocretins), called such for their stimulatory actions on feeding when injected centrally, have previously been localized within the LHA at both the mRNA (Broberger et al, 1998;Elias et al, 1998;Sakurai et al, 1998) and protein level (Cheng et al, 2003;Cutler et al, 2001;Elias et al, 1998). The pattern of staining we observed in the present investigation is congruent with the numerous studies that have extensively mapped the distribution of orexin previously (Cheng et al, 2003;Cutler et al, 2001;Peyron et al, 1998).…”

Section: Discussionsupporting

confidence: 90%

“…The pattern of NOS staining within the hypothalamus has been previously characterized (Cheng et al, 2003;Cutler et al, 2001;Yamada et al, 1996;Yao et al, 2003) and the staining we observed in the present study was essentially identical to that described in these studies. Western blot analysis of protein extracted from the LHA using the antisera revealed a band of 155 kDa (n ϭ 3), which corresponds to the size of nNOS in the rat (Fig.…”

Section: Validation Of Nnos Staining Specificitysupporting

confidence: 89%

“…Despite evidence of the presence of nNOS within the LHA (Cheng et al, 2003;Cutler et al, 2001;Yamada et al, 1996), the effect of an osmotic challenge on protein expression is still currently not known. In light of the evidence supporting a role for both the LHA and NO in the regulation of fluid homeostasis, the aim of the present study was to determine the effects of short-and long-term water deprivation on the expression of nNOS throughout the entire rostrocaudal axis of the LHA of the rat with immunohistochemistry.…”

mentioning

confidence: 99%

See 3 more Smart Citations

Water deprivation increases the expression of neuronal nitric oxide synthase (nNOS) but not orexin‐A in the lateral hypothalamic area of the rat

Yao¹,

Gouraud²,

Paton³

et al. 2005

J of Comparative Neurology

View full text Add to dashboard Cite

The discovery that the lateral hypothalamic area (LHA) might be important in modulating drinking behavior and fluid balance has led to numerous studies aimed at identifying the key neurotransmitters/neuromodulators and pathways involved. While past studies have demonstrated the presence of neuronal nitric oxide synthase (nNOS) within the LHA, its role in the regulation of fluid homeostasis is not known. In light of this, and the mounting evidence suggesting a role for nitric oxide in osmotic regulation within the hypothalamus, this study sought to determine the effects of 24- and 72-hours of water deprivation on nNOS protein expression within the LHA of the rat with immunohistochemistry. In euhydrated control animals we observed nNOS-like immunoreactivity throughout all levels of the LHA. Following 24 hours of dehydration the number of nNOS-like immunopositive neurons was significantly increased in the rostral but not the caudal regions of LHA. Seventy-two hours of water deprivation lead to further increases in nNOS-like immunoreactivity at different levels of the LHA. Interestingly, however, we observed increased nNOS-like immunoreactivity in the caudal regions of the LHA that was not evident after 24 hours of water deprivation. Double-labeling immunofluorescence histochemistry revealed that the nNOS-like immunoreactive neurons were not colocalized with the orexin-A-containing neurons. These results suggest that an osmotic challenge leads to an upregulation of nNOS immunoreactivity within discrete areas of the LHA. This altered neurochemistry within the LHA further highlights the potential importance of nitric oxide and the LHA in central regulation of fluid homeostasis.

show abstract

Section: Discussionsupporting

confidence: 93%

Section: Discussionsupporting

confidence: 90%

Section: Validation Of Nnos Staining Specificitysupporting

confidence: 89%

mentioning

confidence: 99%

See 2 more Smart Citations

Water deprivation increases the expression of neuronal nitric oxide synthase (nNOS) but not orexin‐A in the lateral hypothalamic area of the rat

Yao¹,

Gouraud²,

Paton³

et al. 2005

J of Comparative Neurology

View full text Add to dashboard Cite

show abstract

“…Therefore, we suspected possible involvement of other neuropeptides or modulatory factors contained in the orexinergic neurons. These were dynorphin (6), galanin (16), glutamate (1,32), and nitric oxide (5). These substances are considered deficient in ORX/ATX-Tg mice because almost all of the orexin-containing neurons were ablated in this mutant (17).…”

Section: Discussionmentioning

confidence: 99%

Orexin neuron-mediated skeletal muscle vasodilation and shift of baroreflex during defense response in mice

Zhang

Sakurai²,

Fukuda³

et al. 2006

American Journal of Physiology-Regulatory, Integrative and Comp

View full text Add to dashboard Cite

Zhang, Wei, Takeshi Sakurai, Yasuichiro Fukuda, and Tomoyuki Kuwaki. Orexin neuron-mediated skeletal muscle vasodilation and shift of baroreflex during defense response in mice. Am J Physiol Regul Integr Comp Physiol 290: R1654 -R1663, 2006. First published January 12, 2006 doi:10.1152/ajpregu.00704.2005We have previously shown that some features of the defense response, such as increases in arterial blood pressure (AP), heart rate (HR), and ventilation were attenuated in prepro-orexin knockout (ORX-KO) mice. Here, we examined whether the same was true in orexin neuron-ablated [orexin/ataxin-3 transgenic mice (ORX/ATX-Tg)] mice. In addition, we examined other features of the defense response: skeletal muscular vasodilation and shift of baroreceptor reflex. In both anesthetized and conscious conditions, basal AP in ORX/ATX-Tg mice was significantly lower by ϳ20 mmHg than in wild-type (WT) controls, as was the case in ORX-KO mice. The difference in AP disappeared after treatment with an ␣-blocker but not with a ␤-blocker, indicating lower sympathetic vasoconstrictor outflow. Stimulation of the perifornical area (PFA) in urethane-anesthetized ORX/ATX-Tg mice elicited smaller and shorter-lasting increases in AP, HR, and ventilation, and skeletal muscle vasodilation than in WT controls. In addition, air jet stress-induced elevations of AP and HR were attenuated in conscious ORX/ATX-Tg mice. After pretreatment with a ␤-blocker, atenolol, stimulation of PFA suppressed phenylephrine (50 g/kg iv)-induced bradycardia (⌬HR ϭ Ϫ360 Ϯ 29 beats/ min without PFA stimulation vs. Ϫ166 Ϯ 26 during stimulation) in WT. This demonstrated the resetting of the baroreflex. In ORX/ ATX-Tg mice, however, no significant suppression was observed (Ϫ355 Ϯ 16 without stimulation vs. Ϫ300 Ϯ 30 during stimulation). The present study provided further support for our hypothesis that orexin-containing neurons in PFA play a role as a master switch to activate multiple efferent pathways of the defense response and also operate as a regulator of basal AP.hypothalamus; stress; blood pressure; respiration OREXIN A AND B, also known as hypocretin 1 and 2, respectively, are hypothalamic neuropeptides. They are cleaved from a common precursor molecule, prepro-orexin, undergoing proteolytic processing (33,41). Although the localization of orexin-containing cell bodies is restricted to the hypothalamus, the orexin-containing fibers and terminals are widely distributed in the hypothalamus, thalamus, cerebral cortex, circumventricular organs, brain stem, and spinal cord (13,28). This anatomic feature establishes the basis that orexin contributes to multiple physiological functions, including feeding behavior, energy homeostasis, sleep-wake cycle, and regulation of the autonomic and neuroendocrine systems (25,36,41).At present, there are two genetically engineered mice models of orexin deficiency to study possible roles of intrinsic orexin in physiological functions mentioned above. One is the prepro-orexin knockout (ORX-KO) mouse that was developed by a conv...

show abstract

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

Spina¹,

Langnaese²,

Orlando³

et al. 2004

J of Comparative Neurology

View full text Add to dashboard Cite

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.

show abstract

Morphological study of orexin neurons in the hypothalamus of the Long–Evans rat, with special reference to co-expression of orexin and NADPH-diaphorase or nitric oxide synthase activities

Cited by 37 publications

References 61 publications

Water deprivation increases the expression of neuronal nitric oxide synthase (nNOS) but not orexin‐A in the lateral hypothalamic area of the rat

Water deprivation increases the expression of neuronal nitric oxide synthase (nNOS) but not orexin‐A in the lateral hypothalamic area of the rat

Orexin neuron-mediated skeletal muscle vasodilation and shift of baroreflex during defense response in mice

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

Contact Info

Product

Resources

About