Article date: 1992/6/24
PubMed ID: 1356802
Journal name: European journal of pharmacology (ISSN: 0014-2999)
In order to elucidate the role of excitatory and inhibitory transmitters within the suprachiasmatic nucleus (SCN) in the circadian change of 2-deoxyglucose (2-DG) uptake in this nucleus, the effects of 8-hydroxy-2-(di-n-propylamino) tetralin hydrobromide (8-OH-DPAT), muscimol, flurazepam, pentobarbital and glutamate on uptake of 2-DG by hamster SCN were examined in hypothalamic slice preparations. 2-DG uptake in the SCN was high during the subjective day and low during the subjective night. The high uptake of 2-DG in the SCN during the daytime was inhibited by the superfusion of 8-OH-DPAT, muscimol, flurazepam and pentobarbital in a dose-dependent manner, but the low uptake of 2-DG during the night was unaffected. The low uptake during the night was significantly increased by treatment with glutamate, whereas 2-DG uptake during the day was unaffected. In contrast to the above results, 20 mM KCl and 1 microM tetrodotoxin increased and decreased 2-DG uptake during both the day and night, respectively. The present results strongly suggest that agonists of 5-HT1A receptors and GABAA-benzodiazepine-barbiturate complex receptors regulate the function of the SCN through their inhibitory action on 2-DG uptake during the day, and that glutamate also regulates SCN function through it stimulatory action on 2-DG uptake during the night.
Author List: Tominaga K, Shibata S, Ueki S, Watanabe S
Publication Types: Comparative Study; Journal Article
Substances mentioned in the article: Glutamates; Muscimol; Glutamic Acid; Tetrodotoxin; Potassium Chloride; 8-Hydroxy-2-(di-n-propylamino)tetralin; Deoxyglucose; Pentobarbital; Flurazepam;
Mesh terms: 8-Hydroxy-2-(di-n-propylamino)tetralin/pharmacology; Animals; Circadian Rhythm/drug effects; Cricetinae; Deoxyglucose/pharmacokinetics; Dose-Response Relationship, Drug; Flurazepam/pharmacology; Glutamates/pharmacology; Glutamic Acid; Male; Mesocricetus; Muscimol/pharmacology; Neurons/drug effects; Pentobarbital/pharmacology; Potassium Chloride/pharmacology; Suprachiasmatic Nucleus/drug effects; Tetrodotoxin/pharmacology;