Effect of galanin on food intake in rats: involvement of lateral and ventromedial hypothalamic sites

1993 ◽  
Vol 264 (2) ◽  
pp. R355-R361 ◽  
Author(s):  
R. R. Schick ◽  
S. Samsami ◽  
J. P. Zimmermann ◽  
T. Eberl ◽  
C. Endres ◽  
...  
Keyword(s):  
Food Intake ◽  
Food Consumption ◽  
Paraventricular Nucleus ◽  
Lateral Hypothalamus ◽  
Ventromedial Hypothalamus ◽  
Initial Increase ◽  
Intracerebroventricular Injection ◽  
Fasted Rats ◽  
Stimulation Of ◽  
Cumulative Food Intake

Galanin has previously been reported to elicit feeding in satiated animals when injected into the hypothalamic paraventricular nucleus. It is not known, however, 1) whether this action is due to activation of feeding signals or suppression of satiety signals or both or 2) whether other hypothalamic regions such as the lateral hypothalamus (LH) or the ventromedial hypothalamus (VMH) are involved in this action. The effects of galanin on food intake were therefore examined in satiated and in fasted rats both after intracerebroventricular injection (0.1, 1, and 10 micrograms/10 microliters) and after microinjection (1 and 5 micrograms/0.5 microliters) into the LH and VMH. Twenty minutes after intracerebroventricular injection, galanin significantly and dose dependently augmented food intake by up to sevenfold in freely feeding rats and by up to 79% in fasted animals. The galanin-induced augmentation of cumulative food intake up to 2 h after injection was due to the initial increase in food consumption during the 0 to 20-min interval. This suggests that galanin acts by activation of feeding behavior and not by suppression of satiety signals in these fasted animals, in which satiety signals are presumably not initially operative. Twenty minutes after intrahypothalamic injections into both the LH and VMH, galanin (5 micrograms) significantly increased food consumption, fivefold in freely feeding rats and 30-35% in fasted rats. Thus stimulation of feeding by centrally injected galanin also involves loci within the LH and VMH.

Adrenergic Stimulation of the Rat Diencephalon and its Effect on Food Intake and Hoarding Activity

1970 ◽  
Vol 22 (2) ◽  
pp. 125-132 ◽  
Author(s):  
J. E. Blundell ◽  
L. J. Herberg
Keyword(s):  
Electrical Stimulation ◽  
Food Intake ◽  
Food Deprivation ◽  
Lateral Hypothalamus ◽  
Adrenergic Stimulation ◽  
Feeding Mechanism ◽  
Stimulation Of ◽  
Nutritional Depletion

The diencephalic area most sensitive to microinjections of noradrenaline lay outside the area of the lateral hypothalamus in which feeding can be produced by electrical stimulation. Injection of either area, including injections that caused increased feeding, failed to have any effect on hoarding activity. Since hoarding can be elicited both by food deprivation and by electrical stimulation of the lateral hypothalamus, these findings indicate biochemical, anatomical and motivational differences between the central feeding mechanism sensitive to adrenergic stimulation, and that responding to electrical stimulation or nutritional depletion. The former mechanism may be disinhibitory; the latter, excitatory.

Effect of peptide histidine isoleucine on consummatory behavior in rats

2003 ◽  
Vol 284 (6) ◽  
pp. R1445-R1453 ◽  
Author(s):  
Pawel K. Olszewski ◽  
Michelle M. Wirth ◽  
Timothy J. Shaw ◽  
Martha K. Grace ◽  
Allen S. Levine
Keyword(s):  
Food Intake ◽  
Food Consumption ◽  
Paraventricular Nucleus ◽  
Hypothalamic Paraventricular Nucleus ◽  
Central Nucleus ◽  
Consummatory Behavior ◽  
Inhibitory Influence ◽  
Potent Effect ◽  
Double Immunohistochemistry

Peptide histidine isoleucine (PHI) and VIP are derived from the same precursor. While central VIP decreases food intake, potential effects of PHI on feeding have not been studied. In the current study, we found that PHI administered intracerebroventricularly (ICV) or into the hypothalamic paraventricular nucleus (PVN) or central nucleus of the amygdala (CeA) decreased food consumption in overnight-deprived rats. The magnitude of an anorexigenic response to PHI differed depending on the injection route: ICV-infused peptide evoked the most potent effect. We determined that that only PVN- and CeA-injected PHI did not have aversive consequences. In addition, we infused anorexigenic doses of PHI via the same routes and assessed Fos immunoreactivity of PVN oxytocin (OT) and vasopressin (VP) neurons using double immunohistochemistry. OT and VP are thought to promote feeding termination. PHI increased the percentage of Fos-positive OT neurons regardless of the injection route. PVN- and ICV-infused PHI induced activation of VP cells. We conclude that central PHI has an inhibitory influence on food intake in rats. The PVN, with OT and VP neurons, and CeA may be involved in the mediation of anorexigenic effects of PHI.

Hypothalamic projections of renal afferent nerves in the cat

1980 ◽  
Vol 58 (5) ◽  
pp. 574-576 ◽  
Author(s):  
J. Ciriello ◽  
F. R. Calaresu
Keyword(s):  
Electrical Stimulation ◽  
Arterial Pressure ◽  
Paraventricular Nucleus ◽  
Fluid Balance ◽  
Lateral Hypothalamus ◽  
Discharge Rate ◽  
Renal Nerves ◽  
Preoptic Nucleus ◽  
Afferent Nerves ◽  
Stimulation Of

In 10 cats anaesthetized with chloralose the electrical activity of spontaneously active hypothalamic units was recorded for changes in discharge rate during electrical stimulation of renal afferent nerves. The discharge rate of 141 single units was altered by stimulation of either the ipsilateral or contralateral renal nerves. Most of the responsive units were located in the regions of lateral preoptic nucleus, lateral hypothalamus, and paraventricular nucleus. These results demonstrate that renal afferent nerves provide information to hypothalamic structures known to be involved in the regulation of arterial pressure and fluid balance.

Stimulation of eating by the second messenger cAMP in the perifornical and lateral hypothalamus

1997 ◽  
Vol 273 (1) ◽  
pp. R107-R112 ◽  
Author(s):  
E. R. Gillard ◽  
A. M. Khan ◽  
A. ul-Haq ◽  
R. S. Grewal ◽  
B. Mouradi ◽  
...  
Keyword(s):  
Food Intake ◽  
Lateral Hypothalamus ◽  
Second Messengers ◽  
Second Messenger ◽  
Cyclic Monophosphate ◽  
Camp Analog ◽  
Complex Goal ◽  
Intracellular Action ◽  
Stimulation Of ◽  
Goal Oriented Behavior

Despite intense study of neurotransmitters mediating hypothalamic controls of food intake, little is known about which second messengers are critical for these mechanisms. To determine whether adenosine 3',5'-cyclic monophosphate (cAMP) might participate in these mechanisms, we injected the membrane-permeant cAMP analog 8-bromo-cAMP (8-BrcAMP) hypothalamically in satiated rats. Injection of 8-BrcAMP (10-100 nmol) into the perifornical (PFH) and lateral hypothalamus (LH) dose dependently stimulated food intake of up to 15.7 g in 2 h. Significantly smaller responses were obtained with thalamic injections. In contrast to the strong stimulatory effects of PFH and LH 8-BrcAMP, cAMP and 8-bromo-guanosine 3',5'-cyclic monophosphate (100 nmol) were ineffective, suggesting a chemically specific, intracellular action. Consistent with this, combined PFH injection of 7-deacetyl-7-O-(N-methylpiperazino)-tau-butyryl-forskolin dihydrochloride and 3-isobutyl-1-methylxanthine, agents that increase endogeneous cAMP, stimulated eating of up to 9.9 g in 2 h. These results demonstrate that increases in PFH/LH cAMP can elicit complex, goal-oriented behavior, suggesting an important role for cAMP in hypothalamic mechanisms stimulating food intake.

Modulation of feeding by endogenous sugar acids acting as hunger or satiety factors

1984 ◽  
Vol 246 (4) ◽  
pp. R542-R550 ◽  
Author(s):  
N. Shimizu ◽  
Y. Oomura ◽  
T. Sakata
Keyword(s):  
Food Intake ◽  
Feeding Behavior ◽  
Food Consumption ◽  
Single Neuron ◽  
Cerebral Ventricle ◽  
Neuron Activity ◽  
Hypothalamic Area ◽  
The Third ◽  
Single Neuron Activity ◽  
Fasted Rats

Endogenous sugar acids, 3,4-dihydroxybutanoic acid (2-deoxytetronic acid, 2-DTA) and 2,4,5-trihydroxypentanoic acid (3-deoxypentonic acid, 3-DPA), have been identified in the serum of fasted rats. Effects of these sugar acids on rat feeding behavior and neuron activity were investigated. Injections of 2-DTA (2.5 mumol) into the third cerebral ventricle of chronic rats suppressed food intake and single-neuron activity in the lateral hypothalamic area (LHA). Food consumption was reduced for 24 h, even in 72-h food-deprived rats. The same amounts of 3-DPA elicited feeding and increased LHA single-neuron activity with latencies of 6-8 min. Electrophoretically applied 2-DTA significantly and specifically suppressed activity of glucose-sensitive neurons in the LHA, whereas 3-DPA facilitated the activity. Nonglucose-sensitive LHA neurons were not affected by these sugar acids. The high correlation between modulation of feeding behavior and changes in LHA neuron activity after injection of these sugar acids suggested that 2-DTA may act as an endogenous satiety substance and 3-DPA as a hunger substance. The effects may be mediated through glucose-sensitive neurons in the LHA.

Glucagon-like peptide 1-(7–36) amide acts at lateral and medial hypothalamic sites to suppress feeding in rats

2003 ◽  
Vol 284 (6) ◽  
pp. R1427-R1435 ◽  
Author(s):  
Rafael R. Schick ◽  
Jens P. Zimmermann ◽  
Thomas vorm Walde ◽  
Volker Schusdziarra
Keyword(s):  
Food Intake ◽  
Feeding Behavior ◽  
Effective Dose ◽  
Ventromedial Hypothalamus ◽  
Brain Regions ◽  
Central Administration ◽  
Minimal Effective Dose ◽  
Glucagon Like Peptide ◽  
Glucagon Like Peptide 1 ◽  
Fasted Rats

Glucagon-like peptide 1-(7–36) amide (GLP-1) potently inhibits rat feeding behavior after central administration. Because third ventricular injection of GLP-1 appeared to be less effective than lateral ventricular injection, we have reexamined this issue. In addition, we attempted to identify brain regions other than the paraventricular nucleus of the hypothalamus that are sensitive toward GLP-1-induced feeding suppression. Finally, we examined the local role of endogenous GLP-1 by specific GLP-1 receptor blockade. After lateral ventricular injection, GLP-1 significantly inhibited food intake of 24-h-fasted rats in a dose-dependent fashion with a minimal effective dose of 1 μg. After third ventricular injection, GLP-1 (1 μg) was similarly effective in suppressing food intake, which extends previous findings. Intracerebral microinjections of GLP-1 significantly suppressed food intake in the lateral (LH), dorsomedial (DMH), and ventromedial hypothalamus (VMH), but not in the medial nucleus of the amygdala. The minimal effective dose of GLP-1 was 0.3 μg at LH sites and 1 μg at DMH or VMH sites. LH microinjections of exendin-(9–39) amide, a GLP-1 receptor antagonist, at 1 or 2.5 μg did not alter feeding behavior in 24-h-fasted rats. In satiated animals, however, a single LH injection of 1 μg exendin-(9–39) amide significantly augmented food intake, but only during the first 20 min (0.6 vs. 0.1 g). With three repeated injections of 2.5 μg exendin-(9–39) amide every 20 min, 1-h food intake was significantly increased by 300%. These data strongly support and extend the concept of GLP-1 as a physiological regulator of food intake in the hypothalamus.

scholarly journals Neuropeptide S Stimulates the Hypothalamo-Pituitary-Adrenal Axis and Inhibits Food Intake

Endocrinology ◽  
2006 ◽  
Vol 147 (7) ◽  
pp. 3510-3518 ◽  
Author(s):  
Kirsty L. Smith ◽  
Michael Patterson ◽  
Waljit S. Dhillo ◽  
Sejal R. Patel ◽  
Nina M. Semjonous ◽  
...  
Keyword(s):  
Food Intake ◽  
Hpa Axis ◽  
Paraventricular Nucleus ◽  
Arginine Vasopressin ◽  
Lateral Ventricle ◽  
Neuropeptide S ◽  
Plasma Acth ◽  
Vasopressin Release ◽  
Pituitary Adrenal Axis ◽  
Stimulation Of

Neuropeptide S (NPS) is a recently discovered peptide shown to be involved in the modulation of arousal and fear responses. It has also been shown that lateral ventricle administration of NPS causes a significant decrease in food intake. Neuropeptides involved in the modulation of arousal have been shown to be involved in the regulation of the hypothalamo-pituitary adrenal (HPA) axis and food intake. In this study, we have examined the effect of intracerebroventricular (ICV) administration of NPS on behavior, regulation of the HPA axis, and food intake. ICV NPS significantly increased plasma ACTH and corticosterone 10 and 40 min after injection, respectively. A single ICV injection of NPS caused a significant increase in rearing activity as well as ambulatory movement for up to 45 min after injection. We then studied the effect of paraventricular nucleus (PVN) administration of NPS on the regulation of the HPA axis, behavior, and food intake. There was a significant increase in plasma ACTH and corticosterone after a single NPS PVN injection. Incubation of hypothalamic explants with increasing concentrations of NPS caused a significant increase in CRH and arginine vasopressin release. In addition, PVN administration of NPS dose-dependently inhibited food intake in the first hour after injection, although no effect on food intake was seen after this time. PVN administration of NPS caused a significant increase in rearing activity. These data demonstrate a novel role for NPS in the stimulation of the HPA axis.

Injection of neuropeptide W into paraventricular nucleus of hypothalamus increases food intake

2005 ◽  
Vol 288 (6) ◽  
pp. R1727-R1732 ◽  
Author(s):  
Allen S. Levine ◽  
Raphaelle Winsky-Sommerer ◽  
Salvador Huitron-Resendiz ◽  
Martha K. Grace ◽  
Luis de Lecea
Keyword(s):  
Food Intake ◽  
G Protein ◽  
Paraventricular Nucleus ◽  
Lateral Hypothalamus ◽  
Intracerebroventricular Administration ◽  
G Protein Coupled Receptor ◽  
Endogenous Ligand ◽  
Time Period ◽  
G Protein Coupled ◽  
Paraventricular Nucleus Of Hypothalamus

Neuropeptide W (NPW) is an endogenous ligand for G protein-coupled receptor 7 (GPR7). There are two forms of the peptide, designated as neuropeptide W-23 (NPW23) and neuropeptide W-30 (NPW30). In the current study we found that intracerebroventricular administration of NPW23 increased c-Fos immunoreactivity (IR) in a variety of brain sites, many of which are involved in the regulation of feeding. In particular, we noted that c-Fos IR levels were increased in hypocretin-expressing neurons in the perifornical region of the lateral hypothalamus (LH). We then studied whether injection of NPW23 into the paraventricular nucleus of the hypothalamus (PVN) and the LH increased food intake over a 24-h time period. Intra-PVN injection of NPW23 at doses ranging from 0.1 to 3 nmol increased feeding for up to 4 h, and doses ranging from 0.3 to 3 nmol increased feeding for up to 24 h. In contrast, only the 3-nmol dose of NPW23 increased feeding after administration into the LH. Together, these data suggest a modulatory role for NPW in the control of food intake.

Bombesin, but not amylin, blocks the orexigenic effect of peripheral ghrelin

2006 ◽  
Vol 291 (4) ◽  
pp. R903-R913 ◽  
Author(s):  
Peter Kobelt ◽  
Miriam Goebel ◽  
Andreas Stengel ◽  
Marco Schmidtmann ◽  
Ivo R. van der Voort ◽  
...  
Keyword(s):  
Food Intake ◽  
Neuronal Activity ◽  
Paraventricular Nucleus ◽  
Arcuate Nucleus ◽  
Vehicle Group ◽  
Fos Expression ◽  
Crf Neurons ◽  
Stimulation Of

The interaction between ghrelin and bombesin or amylin administered intraperitoneally on food intake and brain neuronal activity was assessed by Fos-like immunoreactivity (FLI) in nonfasted rats. Ghrelin (13 μg/kg ip) increased food intake compared with the vehicle group when measured at 30 min (g/kg: 3.66 ± 0.80 vs. 1.68 ± 0.42, P < 0.0087). Bombesin (8 μg/kg) injected intraperitoneally with ghrelin (13 μg/kg) blocked the orexigenic effect of ghrelin (1.18 ± 0.41 g/kg, P < 0.0002). Bombesin alone (4 and 8 μg/kg ip) exerted a dose-related nonsignificant reduction of food intake (g/kg: 1.08 ± 0.44, P > 0.45 and 0.55 ± 0.34, P > 0.16, respectively). By contrast, ghrelin-induced stimulation of food intake (g/kg: 3.96 ± 0.56 g/kg vs. vehicle 0.82 ± 0.59, P < 0.004) was not altered by amylin (1 and 5 μg/kg ip) (g/kg: 4.37 ± 1.12, P > 0.69, and 3.01 ± 0.78, respectively, P > 0.37). Ghrelin increased the number of FLI-positive neurons/section in the arcuate nucleus (ARC) compared with vehicle (median: 42 vs. 19, P < 0.008). Bombesin alone (4 and 8 μg/kg ip) did not induce FLI neurons in the paraventricular nucleus of the hypothalamus (PVN) and coadministered with ghrelin did not alter ghrelin-induced FLI in the ARC. However, bombesin (8 μg/kg) with ghrelin significantly increased neuronal activity in the PVN approximately threefold compared with vehicle and ∼1.5-fold compared with the ghrelin group. Bombesin (8 μg/kg) with ghrelin injected intraperitoneally induced Fos expression in 22.4 ± 0.8% of CRF-immunoreactive neurons in the PVN. These results suggest that peripheral bombesin, unlike amylin, inhibits peripheral ghrelin induced food intake and enhances activation of CRF neurons in the PVN.

scholarly journals A reassessment of the role of serotonergic system in the control of feeding behavior

2005 ◽  
Vol 77 (1) ◽  
pp. 103-111 ◽  
Author(s):  
Magda A. Medeiros ◽  
Ricardo H. Costa-e-Sousa ◽  
Emerson L. Olivares ◽  
Wellington S. Côrtes ◽  
Luís C. Reis
Keyword(s):  
Body Weight ◽  
Food Intake ◽  
Feeding Behavior ◽  
The Body ◽  
Serotonergic System ◽  
Initial Increase ◽  
Energetic Balance ◽  
Electrolytic Lesions ◽  
Fasted Rats

The role of serotonergic system in the feeding behaviorwas appraised by electrolytic lesions in the dorsal raphe nucleus (DRN) and administration of para-chlorophenylalanine (PCPA, 3 mg/5 mul, icv). Chronic evaluations were accomplished through 120 and 360 days in PCPA-injected and DRN-lesioned rats, respectively. Acute food intake was evaluated in fasted rats and submitted to injection of PCPA and hydroxytryptophan (LHTP, 30 mg/kg, ip). DRN-lesioned rats exhibited 22-80% increase in food intake up to sixth month, whereas the obesity was evident and sustained by whole period. In PCPA-injected rats was observed an initial increase in the food intake followed by hypophagy from 25th to 30th day and a transitory increase of body weight from 5th to 60th day. In the acute study, the LHTP reverted partially the PCPA-induced increase in food intake of fasted rats suggesting a sustained capacity of decarboxylation of precursor by serotonergic neurons. Slow restoration of the levels of food intake in DRN-lesioned rats reveals a neuroplasticity in the systems that regulate feeding behavior. A plateau on the body weight curve in lesioned rats possibly represents the establishment of a new and higher set point of energetic balance.

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