• Journal of Nutrition and Health
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• v.33 no.5
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• pp.491-496
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• 2000

Food intake is regulated by both central and peripheral mechanisms. In the central nervous, the hypothalamus acts for autonomic and endocrine homeostasis. The paraventricular nucleus(PVN) of hypothalamus is an imprtant site of interaction in central feeding pathways. Neuroepetide Y(NPY)is one of the most powerful neurochemical stimulants of food intake known. Also brain nitric oxide(NO), known as neurotransmitter, is involved in the mechanisms that regulate food intake. In this experiment, 24h fasting mice and anorexia mutant mice have been to examine the expression of NPY, which is the major neuropeptide increasing food intake. Double staining with NPY and nicotinamide-adenine-dinucleotide-phosphate diaphorase(NADPH-d), followed by immunohistochemical method and image analysis, have been used to observe coexisting neurons and the level of expression of each neurons. The results were as follows. 1) NPY-immunoreactivitys reduced immune response of the hypothalamus, particularly paraventricular nucleus(PVN), in anorexia mutant mice. Decreased level of NPY is assumed to be a major pathological factor in anorexia mutant mice. On the other hand, PVN in hypothalamus of fasting mice showed increased immunoreactivity which is in agreement of other researchers. 2) NPY and NADPH-d double staining revealed coexisting neurons in the cerebral cortex. Fasting mice had a tendency to have increased level of coexisting neurons compared to the control group. Compared to the control group, fasting mice express is not increase level of NPY-immunoreactivity, while anorexia mutant mice tended to have a decreased level.

• Korean Journal of Veterinary Research
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• v.36 no.1
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• pp.39-49
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• 1996

The present study was performed to investigate the distribution of neuropeptide Y immunoreactivities in the corpus striatum of the Korean squirrels. The animals were perfused with 4%-paraformaldehyde and the brain was cut serially into $40{\mu}m$ thick coronal sections. Sections either were stained with cresyl violet or were stained immunohistochemically. The corpus striatum was divided into the caudate nucleus, putamen and globus pallidus. Anterior part. however, of the striatum was observed as the combined caudate-putamen. NPY immunoreactive (NPY-IR) neurons were medium-sized. The corpus striatum contained a low level of NPY-IR fibers, whose distribution appeared to be related to the immunoreactive perikarya. Large numbers of NPY-IR neurons in the caudate-putamen and caudate nucleus were expressed in medial and ventral parts. In the anterior part of the putamen NPY-IR neurons were scattered throughout the nucleus; in posterior part were found generally in the lateral and ventral parts. The density of NPY-IR fibers of the putamen were low, whose distribution appeared to be related to the perikarya. The globus pallidus contained NPY-IR fibers only in the lowest density. In brief, NPY-immunoreactivities in the corpus striatum are heterogenous in distribution. These findings may reflect innate characteristics of the specific neural circuit in the corpus striatum itself.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.1
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• pp.35-40
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• 2001

The physiological role of brain neuropeptide Y (NPY) in the central regulation of grass intake in sheep was investigated through a continuous intracerebroventricular (ICV) infusion of NPY at a dose of $5{\mu}g/0.2ml/hr$ for 98.5 hours from day 1 to day 5. Sheep (n=5) were fed for 2 hours once a day, and water and 0.5 M NaCl solution were given ad libitum. Feed intake during ICV NPY infusion increased significantly compared to that during ICV artificial cerebrospinal fluid (CSF) infusion. Water and NaCl intake during ICV NPY infusion remained unchanged. Mean arterial blood pressure (MAP) and plasma osmolality during ICV NPY infusion were not significantly different from those during ICV CSF infusion. On the other hand, plasma glucose concentration during ICV NPY infusion increased significantly compared to that during ICV CSF infusion. The results suggest that brain NPY acts as a hunger factor in brain mechanisms controlling feeding to increase grass intake in sheep.

• The Korean Journal of Physiology and Pharmacology
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• v.5 no.6
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• pp.479-485
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• 2001

The existence of opioid receptors in mammalian cerebellum except human, has not been clearly understood. In the present study, we found that NPY was inducible by morphine in the mouse cerebellar granular and Purkinje cell layers. We performed in situ RT-PCR and immunohistochemistry to characterize the NPY expression. The increase of NPY gene expression by morphine (30 mg/kg, i.p.) was inhibited by pretreatment with not only naloxone (100 mg/kg, i.p.) but also a noncompetitive NMDA antagonist, MK-801 (0.3 mg/kg, i.p.). The competitive NMDA antagonist, AP-5 (0.9 mg/kg, i.p.) slightly attenuated the increased NPY expression by morphine. Also, the finding similar to morphine was shown by NMDA (70 mg/kg, i.p.) treatment. Our results indicate that NPY was inducible by morphine and this might reflect activation of NMDA receptors in granule cells that relay mossy fiber inputs to Purkinje cells via parallel fibers.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.14 no.2
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• pp.171-180
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• 2011

Purpose: The aim of this study was to assess changes in neuropeptide Y (NPY) immunoreactivity in the hypothalamus and interstitial cells of Cajal (ICC) in the small intestine of rats fed high-fat diets (HFD). Methods: Male Sprague-Dawley rats (200~250 g body weight) were randomly divided into two groups, which were the control group (normal chow diet for 6 weeks), and the HFD group (rodent diet with 60% kcal fat for 6 weeks). The immunoreactivity of NPY in the hypothalamus and ICC in the small intestine was evaluated after every feed for 6 weeks. Results: NPY immunoreactivity was observed strongly in the hypothalamic nuclei in the HFD group compared to the control group. The numbers of NPY-immunoreactive (IR) cells were significantly higher in the paraventricular hypothalamic nucleus in the HFD group than in the control group. In the region of Auerbach's plexus (AP) of small intestine, the staining intensity of the ICC-IR cells was reduced in the HFD group compared to the control group. The numbers of ICC in the small intestine with HFD, including ICC in the inner circular and outer longitudinal muscle were significantly lower than in the control group. Conclusion: This study suggested that increasing NPY-IR cells in the hypothalamus may reflect resistance of NPY action after a HFD, and decreasing ICC-IR cells in the small intestine after a HFD is functionally significant in gastrointestinal motility.

• Korean Journal of Veterinary Research
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• v.39 no.3
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• pp.407-416
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• 1999

This study was carried out to investigate the NPY-immunohistochemical characteristics of the olfactory bulb in the striped field mouse(Apodemus agrarius). The animals were anesthesized with thiopental sodium and perfused with 4% paraformaldehyde through left ventricle and aorta. Brains were removed and tranfered 10%, 20% and 30% sucrose. Sections were then cut on a cryostat into $40{\mu}m$-thick. The tissue immunostained with avidin-biotinylated complex method. The main olfactory bulb consisted of seven circumferential laminae : an olfactory nerve fiber layer, a glomerular layer with glomeruli surrounding by periglomerular cells, an external plexiform layer having granule and tufted cells, a mitral cell layer, a narrow internal plexiform layer, a granule cell layer forming several cell rows and a layer of white matter. The accessory olfactory bulb had four layers : an olfactory or vomeronasal nerve fiber layer, a glomerular layer consisting of small glomeruli, a mixed layer not distinguishing the external plexiform/mitral cell/granule cell layers and a granule cell layer. Most of NPY-immunoreactive(NPY-IR) neurons in main olfactory bulb were localized in the deeper portion of granule cell layer, white matter and anterior olfactory nucleus. In addition, some NPY-IR neurons were identified in the external plexiform layer. The shape of NPY-IR neurons of all olfactory bulb were predominant round or oval, sometime multipolar in shape. And most NPY-IR processes were parallel to long axis of white matter. In accessory olfactory bulb, NPY-IR neurons were not found in all region.

• BMB Reports
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• v.48 no.12
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• pp.645-646
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• 2015

The sympathetic nervous system (SNS) or neurotransmitters in the bone marrow microenvironment has been known to regulate hematopoietic stem cell (HSC) functions such as self-renewal, proliferation and differentiation. However, the specific role of neuropeptide Y (NPY) in this process remains relatively unexplored. In this study, we demonstrated that NPY deficient mice have significantly reduced HSC numbers and impaired bone marrow regeneration due to apoptotic destruction of SNS fibers and/or endothelial cells. Moreover, NPY treatment prevented bone marrow impairments in a mouse model of chemotherapy-induced SNS injury, while conditional knockout mice lacking the Y1 receptor in macrophages did not restore bone marrow dysfunction in spite of NPY injection. Transforming growth factor-beta (TGF-β) secreted by NPY-mediated Y1 receptor stimulation in macrophages plays a key role in neuroprotection and HSC survival in the bone marrow. Therefore, this study reveals a new role of NPY in bone marrow HSC microenvironment, and provides an insight into the therapeutic application of this neuropeptide.

• Molecules and Cells
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• v.23 no.1
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• pp.88-93
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• 2007

Neuropeptide Y (NPY) is an orexigenic and hypothermic peptide. To understand its role in hypothermic conditions, male rats were placed in a $24^{\circ}C$ or $4^{\circ}C$ air chamber for 1.5 h. The expression of c-Fos protein, and NPY mRNA and protein, was analyzed in the hypothalamus 1 h-2 h later. The cold treatment increased the number of c-Fos-immunoreactive cells in the paraventricular hypothalamic nucleus (PVN) and arcuate nucleus (ARC). At the same time it decreased the density of NPY-immunoreactive components in the PVN, dorsomedial hypothalamic nucleus and ARC, as well as of NPY transcripts in the PVN and ARC. No colocalization of c-Fos with NPY was detected. These results suggest that short-term cold exposure should reduce indirectly NPY production in some hypothalamic nuclei to facilitate thermogenesis without inducing feeding behavior.

• Clinical and Experimental Pediatrics
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• v.49 no.6
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• pp.677-685
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• 2006

Purpose : This study aimed to investigate whether exogenous thyroxine($T_4$) treatment to alcohol-fed dams would ameliorate the detrimental effects of alcohol on the postnatal development of neuropeptide-Y(NPY)-containing neurons of the cerebral cortex and hippocampus of the offspring. Methods : Time-pregnant rats were divided into three groups. An alcohol-fed group A received 35 calories of liquid alcohol diet daily from gestation day 6; control group B was fed a liquid diet in which dextrin replaced alcohol isocalorically; and alcohol＋$T_4$ group C received 35 calories of liquid alcohol diet and exogenous thyroxine subcutaneously. The features of the growth and maturation of rat brain tissue were observed at 0, 7, 14, 21 and 28 postnatal days via immunohistochemistry. Results : Group C showed prominent NPY immunoreactivity in the cerebral cortex compared to group A and B at P7. In group C, NPY-containing neurons were widely distributed in the all layers of cerebral cortex after P14. Also, numerical decreases of NPY-containing neuron were not found according to increasing age in group C. A decrease of NPY-containing neurons, however, was clearly observed in group A compared to group C at P28. In the hippocampus, similar patterns appeared in groups B and C after P7. Especially, in groups B and C, NPY-containing fibers formed plexus in the cerebral cortex and hippocampus at P14. Conclusion : These results suggest that the increase of NPY synthesis caused by maternal administration of exogenous thyroxine may convalesce fetal alcohol effects, one of the effects of the dysthyroid state following maternal alcohol abuse.

• Korean Journal of Veterinary Research
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• v.40 no.2
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• pp.197-211
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• 2000

The pineal body have been known to be affected by superior cervical ganglia, and most of its nerve fibers containing peptidergic neurotransmitters have been considered to be originated from this ganglia. To confirm this relationships, some peptidergic neurotransmitters were identified in both of pineal body and superior cervical ganglia of the Korean native goat, which were divided into two group; breeding season and non-breeding season. The localizations of two catecholamine-synthesizing enzymes; tyrosine hydroxylase (TH) and dopamine beta-hydroxylase (DBH), were investigated by immunohistochemistry in the superior cervical ganglia and the pineal body of adult Korean native goats. Substance P (SP), calcitonin gene-related peptide (CGRP), vasoactive intestinal polypeptide (VIP), neuropeptide Y (NPY) and galanin (GAL) were also identified in these organs by immunohistochemical and double immunofluorescent methods. In superior cervical ganglia, immunoreactivities for TH and DBH were confirmed in the same ganglion cells. The immunoreactivites for SP, VIP(only in male), NPY and GAL were identified in both of ganglion cell bodies and nerve fibers in the ganglia. CGRP immunoreactivity, however, was observed only in nerve fibers. Most NPY- and VIP-immunoreactive(IR) ganglion cells also contained TH. SP and TH were colocalized in the cell bodies, but not in the nerve fibers. TH immunoreactivity was shown in almost all of ganglion cells in the superior cervical ganglia. The immunoreactivity for NPY had some seasonal variation and was stronger in breeding season than in non-breeding season. In pineal body, lots of TH-IR fibers were observed throughout the parenchyma including the pineal stalk and most of them also contained DBH. SP- and NPY-IR fibers were also immunostained with TH or DBH. But a few SP- and NPY-IR fibers were not colocalized with TH or DBH. Exceptionally, a bipolar neuron-like cell was observed to be immunostained with NPY in the pineal body. A few CGRP and GAL-IR fibers were observed, while VIP-IR fibers were not present. It is concluded that most TH- and DBH-IR fibers as well as the peptidergic immunoreactive fibers of the pineal body might be originated from the superior cervical ganglia. Some peptidergic immunoreactive fibers, however, might be come from other regions of brain. We also suggest that NPY in pineal body plays a important role for pineal function. The seasonal variation of NPY immunoreactivity indicates that the synthesis and use of NPY may be different between in breeding and non-breeding seasons.