Effects of intraventricular injections of gamma-aminobutyric acid and related substances on feeding behavior in satiated sheep

1984 ◽  
Vol 62 (10) ◽  
pp. 1296-1299 ◽  
Author(s):  
J. R. Seoane ◽  
F. Dumont ◽  
C. L. Girard ◽  
L. Bédard ◽  
J. J. Matte
Keyword(s):  
Feeding Behavior ◽  
Feed Intake ◽  
Aminobutyric Acid ◽  
Gamma Aminobutyric Acid ◽  
Gaba Agonist ◽  
Lateral Ventricles ◽  
Related Substances ◽  
Intraventricular Injections ◽  
Gaba Antagonist

Feed intake was measured following injections of gamma-aminobutyric acid (GABA), muscimol (a GABA agonist), and picrotoxin (a GABA antagonist) into the lateral ventricles of satiated sheep. Doses ranging from 0.20 to 3200 nmol of GABA did not affect feeding behavior at 15, 30, 60, and 120 min postinjection. A dose of 160 nmol of muscimol induced a marked increase in feeding, comparable to that provoked by an injection of 78 μmol of pentobarbital. Muscimol-induced feeding was blocked effectively by a preinjection of picrotoxin. These observations implicate that neurons sensitive to gamma-aminobutyric acid may be involved in the control of feeding behavior in ruminants.

Studies of the role of gamma-aminobutyric acid in the hypothalamic control of feed intake in sheep

1985 ◽  
Vol 63 (10) ◽  
pp. 1297-1301 ◽  
Author(s):  
C. L. Girard ◽  
J. R. Seoane ◽  
J. J. Matte
Keyword(s):  
Dose Response ◽  
Feed Intake ◽  
Gaba Receptors ◽  
Response Curve ◽  
Aminobutyric Acid ◽  
Gamma Aminobutyric Acid ◽  
Gaba Antagonists ◽  
Gaba Agonist ◽  
Hypothalamic Control

Fourteen sheep were used to study the role of gamma-aminobutyric acid (GABA) on the hypothalamic control of feed intake. Injections (1 μL) of pentobarbital (262 nmol) into preoptic and paraventricular areas induced feeding in satiated sheep. Injections of GABA into the same loci gave variable results, probably because the neuronal and glial uptake of GABA limits its effects. Muscimol, a GABA agonist with a higher affinity for postsynaptic GABA receptors than GABA, injected at doses from 0 to 0.750 nmol, gave a cubic dose–response curve; the highest feed intake was measured at 0.5 nmol. The response induced by muscimol was blocked by preinjections of two GABA antagonists, picrotoxin and bicuculline, with picrotoxin being more effective than bicuculline. Muscimol responsive loci were identified mainly in the preoptic, paraventricular, and anterior hypothalamus. The data suggests that neurons sensitive to gamma-aminobutyric acid may be implicated in the control of feed intake in sheep.

Nucleus accumbens to globus pallidus GABA projection subserving ambulatory activity

1980 ◽  
Vol 238 (1) ◽  
pp. R65-R69 ◽  
Author(s):  
D. L. Jones ◽  
G. J. Mogenson
Keyword(s):  
Nucleus Accumbens ◽  
Synergistic Effect ◽  
Globus Pallidus ◽  
Aminobutyric Acid ◽  
Gamma Aminobutyric Acid ◽  
Ambulatory Activity ◽  
Gaba Antagonist ◽  
Dose Dependent

The present experiments investigated the hypothesis of a projection relating to the release of gamma-aminobutyric acid (GABA) from the nucleus accumbens to the globus pallidus subserving ambulatory activity in the rat. The GABA antagonist picrotoxin, microinjected into the globus pallidus, elicited dose-dependent increases in ambulatory activity. The administration of dopamine into the nucleus accumbens had a synergistic effect and further stimulated ambulatory activity. GABA injected into the ventral posterior globus pallidus significantly attenuated the ambulatory activity stimulated by injecting dopamine into the nucleus accumbens. These observations provide evidence of a GABAergic projection from the nucleus accumbens to the globus pallidus and implicate it in the initiation of ambulatory activity.

GABA antagonism reverses hypoxic respiratory depression in the cat

1990 ◽  
Vol 69 (4) ◽  
pp. 1296-1301 ◽  
Author(s):  
J. E. Melton ◽  
J. A. Neubauer ◽  
N. H. Edelman
Keyword(s):  
Respiratory Depression ◽  
Marked Reduction ◽  
Seizure Activity ◽  
Firing Frequency ◽  
Aminobutyric Acid ◽  
Respiratory Neurons ◽  
Maximum Effect ◽  
Gamma Aminobutyric Acid ◽  
Gaba Antagonist

We assessed the role of gamma-aminobutyric acid (GABA) as a potential causative agent of hypoxic respiratory depression by monitoring the response of the phrenic neurogram to systemic infusion of the GABA antagonist bicuculline (0.01 mg.kg-1.min-1) under control conditions and during isocapnic brain hypoxia produced by CO inhalation in separate groups of anesthetized, glomectomized, vagotomized, paralyzed, and ventilated cats with blood pressure held constant. The maximum effect of bicuculline in subseizure doses in control cats was to increase minute phrenic activity to 151 +/- 14% of preinfusion values. Infusion was continued until seizure activity was seen in the electroencephalogram. A 53% decrease of arterial O2 content resulted in a marked reduction of both peak phrenic amplitude and phrenic firing frequency to 16 and 64% of control values, respectively. Infusion of bicuculline while the level of hypoxia was maintained constant restored both peak phrenic amplitude and phrenic firing frequency to prehypoxic levels. The maximum effect of bicuculline was to increase minute phrenic activity to 123 +/- 13% of the prehypoxic value. These results suggest that although GABA has only a modest role in determining the output of the control phrenic neurogram, a significant portion of the phrenic depression that occurs during hypoxia can be attributed to inhibition of respiratory neurons by GABA.

Role of gamma-aminobutyric acid in regulating feed intake in commercial broilers reared under normal and heat stress conditions.

2019 ◽  
Vol 84 ◽  
pp. 164-175 ◽  
Author(s):  
Karima El-Naggar ◽  
Seham El-Kassas ◽  
Safaa E. Abdo ◽  
Abeer A.K. Kirrella ◽  
Rasha A. Al wakeel
Keyword(s):  
Heat Stress ◽  
Feed Intake ◽  
Stress Conditions ◽  
Aminobutyric Acid ◽  
Gamma Aminobutyric Acid

Topographic studies of the effects of microinjections of muscimol on the hypothalamic control of feed intake in sheep

1986 ◽  
Vol 64 (4) ◽  
pp. 406-410 ◽  
Author(s):  
C. L. Girard ◽  
J. R. Seoane ◽  
J. J. Matte
Keyword(s):  
Feed Intake ◽  
Aminobutyric Acid ◽  
Gamma Aminobutyric Acid ◽  
Anatomical Basis ◽  
Medial Hypothalamus ◽  
Hypothalamic Control ◽  
Feeding Systems

Ten sheep were used to define the anatomical basis for the feeding systems sensitive to gamma-aminobutyric acid, by using intrahypothalamic microinjections of the gamma-aminobutyric acid agonist, muscimol. In satiated sheep, 1 μL of muscimol (0.5 nmol/μL) elicited feeding when injected into paraventricular, ventromedial, and anterior hypothalamic areas. Similar injections into 39 sites tested in 6-h fasted sheep failed to decrease feed intake. The data suggest that neurons sensitive to gamma-aminobutyric acid in medial hypothalamus may be involved in the initiation of feeding.

scholarly journals Decrease of Consciousness Level Caused by Baclofen; a Case Report

2021 ◽  
Author(s):  
Hamideh Ebrahimi ◽  
Meimanat Hosseini
Keyword(s):  
Spinal Cord ◽  
Case Report ◽  
Muscle Tone ◽  
Albumin Level ◽  
Aminobutyric Acid ◽  
Gamma Aminobutyric Acid ◽  
Case Presentation ◽  
Gaba Agonist ◽  
Consciousness Level ◽  
Level Of Consciousness

Abstract Background: The side effects of drug use can have different consequences, from allergies to death. Among the drugs used to relieve chronic spasms is baclofen. Baclofen is a gamma-aminobutyric acid (GABA) agonist that is commonly administered orally and acts on the spinal cord. A few studies have been reported on mortality from baclofen. Case presentation: This present study reported a case of decreased consciousness and drowsiness, and severe decrease in muscle tone as a result of taking only 50 mg of baclofen.Conclusion: Level of consciousness can be decreased following the administration of baclofen but it is not permanent. Nurses are recommended to check albumin level of the blood as an intervening factor and pay attention to patients’ responses to baclofen.

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