1. GABA(A) and GABA(B) receptors in the anterior piriform cortex modulate feeding in rats.
- Author
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Truong BG, Magrum LJ, and Gietzen DW
- Subjects
- Animals, Baclofen pharmacology, Bicuculline pharmacology, Feeding Behavior drug effects, Food, Formulated adverse effects, GABA Agonists pharmacology, GABA Antagonists pharmacology, Male, Muscimol pharmacology, Neural Inhibition drug effects, Neural Inhibition physiology, Neurons drug effects, Neurons metabolism, Olfactory Pathways cytology, Olfactory Pathways drug effects, Oligonucleotide Array Sequence Analysis, RNA, Messenger metabolism, Rats, Rats, Sprague-Dawley, Receptors, GABA-A drug effects, Receptors, GABA-A genetics, Receptors, GABA-B drug effects, Receptors, GABA-B genetics, Threonine deficiency, Threonine pharmacology, Amino Acids deficiency, Baclofen analogs & derivatives, Feeding Behavior physiology, Food Deprivation physiology, Olfactory Pathways metabolism, Receptors, GABA-A metabolism, Receptors, GABA-B metabolism, gamma-Aminobutyric Acid metabolism
- Abstract
The effects of GABA(A) and GABA(B) receptors in the anterior piriform cortex (APC) on intake of an amino acid imbalanced diet and a basal diet were evaluated in rats. Administration of muscimol (GABA(A) receptor agonist) to the APC immediately suppressed ingestion of both amino acid imbalanced and basal diets. Central administration of bicuculline (a GABA(A) receptor antagonist) stimulated feeding of the amino acid imbalanced diet but had no effect on intake of the basal diet. The GABA(B) receptor antagonist phaclofen decreased consumption of the basal diet but did not affect consumption of the amino acid imbalanced diet. These findings demonstrate that manipulation of GABA-sensitive cells in the APC can have a pronounced effect on feeding behavior that is not selective to aminoprivic feeding. However, these data suggest that GABA(A) and GABA(B) receptors may function as regulators that are activated by monoaminergic systems and neuropeptides in response to amino acid imbalanced diet intake. Inhibitory effects of GABA(A) and GABA(B) receptors may modulate the pyramidal cells, contributing to the reduced feeding response to the amino acid imbalanced diet. Also, transcription of mRNA for both GABA receptors and the GABA reuptake transporter was affected by a threonine deficient but not a corrected diet, compared to the basal diet. Taken together, these results support the involvement of GABA receptors in the APC in feeding in general and the responses to amino acid deprivation in vivo.
- Published
- 2002
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