Pathways of Fos expression in locus ceruleus, dorsal vagal complex, and PVN in response to intestinal lipid

1997 ◽  
Vol 273 (6) ◽  
pp. R2059-R2071 ◽  
Author(s):  
Hubert Mönnikes ◽  
Gerd Lauer ◽  
Christoph Bauer ◽  
Johannes Tebbe ◽  
Tillmann T. Zittel ◽  
...  

Exogenous cholecystokinin (CCK) injected peripherally mimics effects of lipid entering the intestine on food intake and gastric motility via vagal afferents and induces c- fos expression in the locus ceruleus complex (LCC), nucleus of the solitary tract (NTS), area postrema (AP), and paraventricular nucleus (PVN). However, the role of peripheral endogenous CCK in induction of c- fos expression in the brain at ingestion of nutrients is controversial. In awake rats, intraduodenal lipid infusion markedly increased Fos protein-like immunoreactivity (FLI) in these brain nuclei. Perivagal capsaicin pretreatment reduced the increase of FLI in the LCC, NTS, and PVN by 66–86% and in the AP by 46%. The CCK-A receptor antagonist MK-329 (0.1 mg/kg ip) diminished the FLI increase in LC, NTS, AP, and PVN by 39–100%; the CCK-B receptor antagonist L-365,260 reduced the increased FLI in the AP by 54%. After capsaicin pretreatment, both CCK antagonists had additional inhibitory effects only on FLI in the AP. These findings suggest that entry of lipid into the intestine activates c- fos in the LCC, NTS, and PVN predominantly via CCK-A receptors on vagal afferents and in the AP via vagal and nonvagal pathways, as well as CCK-B and CCK-A receptors.

2003 ◽  
Vol 285 (3) ◽  
pp. G566-G576 ◽  
Author(s):  
Marja D. Van Sickle ◽  
Lorraine D. Oland ◽  
Ken Mackie ◽  
Joseph S. Davison ◽  
Keith A. Sharkey

The aim of this study was to investigate the efficacy, receptor specificity, and site of action of Δ9-tetrahydrocannabinol (THC) as an antiemetic in the ferret. THC (0.05-1 mg/kg ip) dose-dependently inhibited the emetic actions of cisplatin. The ED50 for retching was ∼0.1 mg/kg and for vomiting was 0.05 mg/kg. A specific cannabinoid (CB)1 receptor antagonist SR-141716A (5 mg/kg ip) reversed the effect of THC, whereas the CB2 receptor antagonist SR-144528 (5 mg/kg ip) was ineffective. THC applied to the surface of the brain stem was sufficient to inhibit emesis induced by intragastric hypertonic saline. The site of action of THC in the brain stem was further assessed using Fos immunohistochemistry. Fos expression induced by cisplatin in the dorsal motor nucleus of the vagus (DMNX) and the medial subnucleus of the nucleus of the solitary tract (NTS), but not other subnuclei of the NTS, was significantly reduced by THC rostral to obex. At the level of the obex, THC reduced Fos expression in the area postrema and the dorsal subnucleus of the NTS. The highest density of CB1 receptor immunoreactivity was found in the DMNX and the medial subnucleus of the NTS. Lower densities were observed in the area postrema and dorsal subnucleus of the NTS. Caudal to obex, there was moderate density of staining in the commissural subnucleus of the NTS. These results show that THC selectively acts at CB1 receptors to reduce neuronal activation in response to emetic stimuli in specific regions of the dorsal vagal complex.


2017 ◽  
Vol 51 (2) ◽  
pp. 73-83
Author(s):  
J. Osacka ◽  
L. Horvathova ◽  
Z. Majercikova ◽  
Alexander Kiss

AbstractObjective. Fos protein expression in catecholamine-synthesizing neurons of the substantia nigra (SN) pars compacta (SNC, A8), pars reticulata (SNR, A9), and pars lateralis (SNL), the ventral tegmental area (VTA, A10), the locus coeruleus (LC, A6) and subcoeruleus (sLC), the ventrolateral pons (PON-A5), the nucleus of the solitary tract (NTS-A2), the area postrema (AP), and the ventrolateral medulla (VLM-A1) was quantitatively evaluated aft er a single administration of asenapine (ASE) (designated for schizophrenia treatment) in male Wistar rats preconditioned with a chronic unpredictable variable mild stress (CMS) for 21 days. Th e aim of the present study was to reveal whether a single ASE treatment may 1) activate Fos expression in the brain areas selected; 2) activate tyrosine hydroxylase (TH)-synthesizing cells displaying Fos presence; and 3) be modulated by CMS preconditioning.Methods. Control (CON), ASE, CMS, and CMS+ASE groups were used. CMS included restraint, social isolation, crowding, swimming, and cold. Th e ASE and CMS+ASE groups received a single dose of ASE (0.3 mg/kg, s.c.) and CON and CMS saline (300 μl/rat, s.c.). The animals were sacrificed 90 min aft er the treatments. Fos protein and TH-labeled immunoreactive perikarya were analyzed on double labeled histological sections and enumerated on captured pictures using combined light and fluorescence microscope illumination.Results. Saline or CMS alone did not promote Fos expression in any of the structures investigated. ASE alone or in combination with CMS elicited Fos expression in two parts of the SN (SNC, SNR) and the VTA. Aside from some cells in the central gray tegmental nuclei adjacent to LC, where a small number of Fos profiles occurred, none or negligible Fos occurrence was detected in the other structures investigated including the LC and sLC, PON-A5, NTS-A2, AP, and VLM-A1. CMS preconditioning did not infl uence the level of Fos induction in the SN and VTA elicited by ASE administration. Similarly, the ratio between the amount of free Fos and Fos colocalized with TH was not aff ected by stress preconditioning in the SNC, SNR, and the VTA.Conclusions. Th e present study provides an anatomical/functional knowledge about the nature of the acute ASE treatment on the catecholamine-synthesizing neurons activity in certain brain structures and their missing interplay with the CMS preconditioning.


1999 ◽  
Vol 277 (3) ◽  
pp. R667-R674 ◽  
Author(s):  
Lixin Wang ◽  
Sylvain Cardin ◽  
Vicente Martínez ◽  
Yvette Taché ◽  
K. C. Kent Lloyd

The role of CCK in mediating neuronal activity in the brain in response to dietary carbohydrate was measured by detecting Fos immunoreactivity in response to duodenal glucose load in rats after administration of the CCK-A receptor antagonist devazepide. In adult, male Sprague-Dawley rats, infusion for 30 min of 545 mg (2.18 kcal) dextrose through a duodenal cannula induced Fos expression in the nucleus of the solitary tract (NTS), area postrema (AP), lateral division of the central nucleus of the amygdala (CeAL), and the external subnucleus of the lateral parabrachial nucleus (LPBE). Devazepide treatment (1 mg/kg) attenuated Fos expression in the NTS and AP by 81 and 78%, respectively, but not in the CeAL or LPBE. These results indicate that central neuronal activation is elicited by dietary glucose in the intestinal lumen and that activation of neurons in the NTS and AP is mediated by CCK-A receptors.


2010 ◽  
Vol 299 (2) ◽  
pp. R623-R631 ◽  
Author(s):  
Catarina S. Potes ◽  
Victoria F. Turek ◽  
Rebecca L. Cole ◽  
Calvin Vu ◽  
Barbara L. Roland ◽  
...  

Circulating amylin inhibits food intake via activation of the area postrema (AP). The aim of this study was to identify the neurochemical phenotype of the neurons mediating amylin's hypophagic action by immunohistochemical and feeding studies in rats. Expression of c-Fos protein was used as a marker for neuronal activation and dopamine-β-hydroxylase (DBH), the enzyme-catalyzing noradrenaline synthesis, as a marker for noradrenergic neurons. We found that ∼50% of amylin-activated AP neurons are noradrenergic. To clarify the functional role of these neurons in amylin's effect on eating, noradrenaline-containing neurons in the AP were lesioned using a saporin conjugated to an antibody against DBH. Amylin (5 or 20 μg/kg sc)-induced anorexia was observed in sham-lesioned rats with both amylin doses. Rats with a lesion of > 50% of the noradrenaline neurons were unresponsive to the low dose of amylin (5 μg/kg) and only displayed a reduction in food intake 60 min after injection of the high amylin dose (20 μg/kg). In a terminal experiment, the same rats received amylin (20 μg/kg) or saline. The AP and nucleus of the solitary tract (NTS) were stained for DBH to assess noradrenaline lesion success and for c-Fos expression to evaluate amylin-induced neuronal activation. In contrast to sham-lesioned animals, noradrenaline-lesioned rats did not show a significant increase in amylin-induced c-Fos expression in the AP and NTS. We conclude that the noradrenergic neurons in the AP mediate at least part of amylin's hypophagic effect.


2011 ◽  
Vol 301 (2) ◽  
pp. R448-R455 ◽  
Author(s):  
Jason Wright ◽  
Carlos Campos ◽  
Thiebaut Herzog ◽  
Mihai Covasa ◽  
Krzysztof Czaja ◽  
...  

Intraperitoneal injection of CCK reduces food intake and triggers a behavioral pattern similar to natural satiation. Reduction of food intake by CCK is mediated by vagal afferents that innervate the stomach and small intestine. These afferents synapse in the hindbrain nucleus of the solitary tract (NTS) where gastrointestinal satiation signals are processed. Previously, we demonstrated that intraperitoneal (IP) administration of either competitive or noncompetitive N-methyl-d-aspartate (NMDA) receptor antagonists attenuates reduction of food intake by CCK. However, because vagal afferents themselves express NMDA receptors at both central and peripheral endings, our results did not speak to the question of whether NMDA receptors in the brain play an essential role in reduction of feeding by CCK. We hypothesized that activation of NMDA receptors in the NTS is necessary for reduction of food intake by CCK. To test this hypothesis, we measured food intake following IP CCK, subsequent to NMDA receptor antagonist injections into the fourth ventricle, directly into the NTS or subcutaneously. We found that either fourth-ventricle or NTS injection of the noncompetitive NMDA receptor antagonist MK-801 was sufficient to inhibit CCK-induced reduction of feeding, while the same antagonist doses injected subcutaneously did not. Similarly fourth ventricle injection of d-3-(2-carboxypiperazin-4-yl)-1-propenyl-1-phosphoric acid (d-CPPene), a competitive NMDA receptor antagonist, also blocked reduction of food intake following IP CCK. Finally, d-CPPene injected into the fourth ventricle attenuated CCK-induced expression of nuclear c-Fos immunoreactivity in the dorsal vagal complex. We conclude that activation of NMDA receptors in the hindbrain is necessary for the reduction of food intake by CCK. Hindbrain NMDA receptors could comprise a critical avenue for control and modulation of satiation signals to influence food intake and energy balance.


1998 ◽  
Vol 275 (1) ◽  
pp. R63-R68 ◽  
Author(s):  
Christopher T. Simons ◽  
Vladimir A. Kulchitsky ◽  
Naotoshi Sugimoto ◽  
Louis D. Homer ◽  
Miklos Székely ◽  
...  

Recent evidence has suggested a role of abdominal vagal afferents in the pathogenesis of the febrile response. The abdominal vagus consists of five main branches (viz., the anterior and posterior celiac branches, anterior and posterior gastric branches, and hepatic branch). The branch responsible for transducing a pyrogenic signal from the periphery to the brain has not as yet been identified. In the present study, we address this issue by testing the febrile responsiveness of male Wistar rats subjected to one of four selective vagotomies: celiac (CBV), gastric (GBV), hepatic (HBV), or sham (SV). In the case of CBV, GBV, and HBV, only the particular vagal branch(es) was cut; for SV, all branches were left intact. After the postsurgical recovery (26–29 days), the rats had a catheter implanted into the jugular vein. On days 29–32, their colonic temperature (Tc) responses to a low dose (1 μg/kg) of Escherichia colilipopolysaccharide (LPS) were studied. Three days later, the animals were subjected to a 24-h food and water deprivation, and the effectiveness of the four vagotomies to induce gastric food retention, pancreatic hypertrophy, and impairment of the portorenal osmotic reflex was assessed by weighing the stomach and pancreas and measuring the specific gravity of bladder urine, respectively. Stomach mass, pancreas mass, and urine density successfully separated the four experimental groups into four distinct clusters, thus confirming that each type of vagotomy had a different effect on the indexes measured. The Tc responses of SV, CBV, and GBV rats to LPS did not differ and were characterized by a latency of ∼40 min and a maximal rise of 0.7 ± 0.1, 0.6 ± 0.1, and 0.9 ± 0.2°C, respectively. The fever response of the HBV rats was different; practically no Tc rise occurred (0.1 ± 0.2°C). The HBV appeared to be the only selective abdominal vagotomy affecting the febrile responsiveness. We conclude, therefore, that the hepatic vagus plays an important role in the transduction of a pyrogenic signal from the periphery to the brain.


1999 ◽  
Vol 277 (2) ◽  
pp. R532-R540 ◽  
Author(s):  
Kathleen S. Curtis ◽  
J. Thomas Cunningham ◽  
Cheryl M. Heesch

Fos and dopamine β-hydroxylase immunoreactivity were evaluated in the brain stems of 21-day pregnant and virgin female rats injected with either hydralazine (HDZ; 10 mg/kg iv) or vehicle. HDZ produced significant hypotension in both groups, although baseline blood pressure was lower in pregnant rats (96 ± 2.5 mmHg) than in virgin female rats (121 ± 2.8 mmHg). There were no differences in Fos immunoreactivity in the brain stems of pregnant and virgin female rats after vehicle treatment. HDZ-induced hypotension significantly increased Fos expression in both groups; however, the magnitude of the increases differed in the caudal ventrolateral medulla (CVL), the area postrema (AP), and the rostral ventrolateral medulla (RVL). Fos expression after HDZ in pregnant rats was augmented in noncatecholaminergic neurons of the CVL but was attenuated in the AP and in noncatecholaminergic neurons in the RVL. These results are consistent with differences in the sympathetic response to hypotension between pregnant and virgin female rats and indicate that the central response to hypotension may be different in pregnant rats.


2004 ◽  
Vol 286 (3) ◽  
pp. R451-R464 ◽  
Author(s):  
Hakan S. Orer ◽  
Gerard L. Gebber ◽  
Shaun W. Phillips ◽  
Susan M. Barman

We tested the hypothesis that blockade of N-methyl-d-aspartate (NMDA) and non-NMDA receptors on medullary lateral tegmental field (LTF) neurons would reduce the sympathoexcitatory responses elicited by electrical stimulation of vagal, trigeminal, and sciatic afferents, posterior hypothalamus, and midbrain periaqueductal gray as well as by activation of arterial chemoreceptors with intravenous NaCN. Bilateral microinjection of a non-NMDA receptor antagonist into LTF of urethane-anesthetized cats significantly decreased vagal afferent-evoked excitatory responses in inferior cardiac and vertebral nerves to 29 ± 8 and 24 ± 6% of control ( n = 7), respectively. Likewise, blockade of non-NMDA receptors significantly reduced chemoreceptor reflex-induced increases in inferior cardiac (from 210 ± 22 to 129 ± 13% of control; n = 4) and vertebral nerves (from 253 ± 41 to 154 ± 20% of control; n = 7) and mean arterial pressure (from 39 ± 7 to 21 ± 5 mmHg; n = 8). Microinjection of muscimol, but not an NMDA receptor antagonist, caused similar attenuation of these excitatory responses. Sympathoexcitatory responses to the other stimuli were not attenuated by microinjection of a non-NMDA receptor antagonist or muscimol into LTF. In fact, excitatory responses elicited by stimulation of trigeminal, and in some cases sciatic, afferents were enhanced. These data reveal two new roles for the LTF in control of sympathetic nerve activity in cats. One, LTF neurons are involved in mediating sympathoexcitation elicited by activation of vagal afferents and arterial chemoreceptors, primarily via activation of non-NMDA receptors. Two, non-NMDA receptor-mediated activation of other LTF neurons tonically suppresses transmission in trigeminal-sympathetic and sciatic-sympathetic reflex pathways.


2010 ◽  
Vol 298 (6) ◽  
pp. R1475-R1484 ◽  
Author(s):  
Thomas A. Lutz

Amylin is an important player in the control of nutrient fluxes. Amylin reduces eating via a meal size effect by promoting meal-ending satiation. This effect seems to depend on a direct action in the area postrema (AP), which is an area rich in amylin receptors. Subsequent to the activation of AP neurons, the neural signal is conveyed to the forebrain via relays involving the nucleus of the solitary tract (NTS) and the lateral parabrachial nucleus (lPBN) to the lateral hypothalamic area (LHA) and other hypothalamic nuclei. While the NTS and lPBN seem to be necessary for amylin's eating inhibitory effect, the role of the LHA has not yet been fully investigated. Amylin may also act as an adiposity signal. Plasma levels of amylin are higher in obese individuals, and chronic infusion of amylin into the brain reduces body weight gain and adiposity; chronic infusion of an amylin receptor antagonist into the brain increases body adiposity. Amylin increases energy expenditure in rats; this effect occurs under various experimental conditions after peripheral and central administration. Together, these animal data, but also clinical data in humans, indicate that amylin is a promising candidate for the treatment of obesity; effects are most pronounced when amylin is combined with leptin. Finally, recent findings indicate that amylin acts as a neurotrophic factor in specific brain stem areas. Whether this effect may be relevant under physiological conditions requires further studies.


1980 ◽  
Vol 59 (s6) ◽  
pp. 267s-269s ◽  
Author(s):  
Julianna E. Szilagyi ◽  
C. M. Ferrario

1. Intra-vertebral artery-administered angiotensin II acts at the area postrema to facilitate central sympathetic vasomotor activity. Recent evidence suggests a possible role of the opiate system in the mechanism of action of angiotensin II at the level of the brain stem. 2. In these experiments, we show that the morphine antagonist naloxone reduces significantly the magnitude of the pressor response to vertebral artery-infused angiotensin II. 3. Morphine, in contrast, doubled the peak of the vertebral response to identical doses of the peptide. Neither naloxone nor morphine affected the pressor responses to intravenously administered angiotensin II. 4. The data suggest that the endogenous opiate system in the medulla modulates the cardiovascular effects of angiotensin II at the level of the area postrema.


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