Glucagon-like peptide-1 modulates neuronal activity in the rat's hippocampus.
In order to assess effects of glucagon-like peptide-1 (GLP-1) in the brain excluding the hypothalamus, the effects of GLP-1 (7-36) amide, a naturally produced active fragment, on the electroencephalogram and hippocampal single unit activities of anesthetized male Wistar rats were examined. I.c.v. injection of GLP-1 (7-36) amide decreased the hippocampal theta wave duration. Juxtacellular administration of GLP-1 (7-36) amide first increased and then decreased single unit activities recorded in the hippocampal CA1, which effects were antagonized by exendin (9-39) amide, a GLP-1 receptor antagonist, or 6-cyano-7-nitroquinoxaline-2,3-dione, a non-NMDA type glutamate receptor antagonist. These results indicate that GLP-1 receptors exist in the hippocampus and are involved in modulating hippocampal activity through an increase in the release of excitatory amino acid transmitters.
Oka
J I
JI
Department of Chemical Pharmacology, Faculty of Pharmaceutical Sciences, Meijo University, Nagoya, Japan.
Goto
N
N
Kameyama
T
T
D000818:Animals; D001224:Aspartic Acid / Q000378:metabolism; D002540:Cerebral Cortex / Q000502:physiology; D004569:Electroencephalography; D005934:Glucagon / Q000502:physiology*; D052216:Glucagon-Like Peptide 1; D000067757:Glucagon-Like Peptide-1 Receptor; D004763:Glucagon-Like Peptides; D018698:Glutamic Acid / Q000378:metabolism; D005973:Glutamine / Q000378:metabolism; D006624:Hippocampus / Q000166:cytology / Q000502:physiology*; D007276:Injections, Intraventricular; D008297:Male; D009474:Neurons / Q000502:physiology*; D010446:Peptide Fragments / Q000494:pharmacology / Q000502:physiology*; D010455:Peptides / Q000494:pharmacology; D011498:Protein Precursors / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D018027:Receptors, Glucagon / Q000037:antagonists & inhibitors; D013268:Stimulation, Chemical; D014697:Ventromedial Hypothalamic Nucleus / Q000166:cytology / Q000378:metabolism
C000593835:Glp1r protein, rat; D000067757:Glucagon-Like Peptide-1 Receptor; D010446:Peptide Fragments; D010455:Peptides; D011498:Protein Precursors; D018027:Receptors, Glucagon; D005973:Glutamine; C055453:glucagon-like peptide 1 (7-36)amide; D001224:Aspartic Acid; D018698:Glutamic Acid; C083773:exendin (9-39); D004763:Glucagon-Like Peptides; D052216:Glucagon-Like Peptide 1; D005934:Glucagon; C055454:glucagon-like peptide 1 (1-36)amide