Bicuculline blocks neuropeptide Y-induced phase advances when microinjected in the suprachiasmatic nucleus of syrian hamsters

• Published in: Brain research Vol. 675; no. 1; pp. 333 - 336
• Main Authors: Huhman, K.L., Babagbemi, T.O., Albers, H.E.
• Format: Journal Article
• Language: English
• Published: London Elsevier B.V 27.03.1995; Amsterdam Elsevier; New York, NY
• Subjects: Animals; Bicuculline - administration & dosage; Bicuculline - pharmacology; Biological and medical sciences; Chronobiology; Circadian rhythm; Cricetinae; Fundamental and applied biological sciences. Psychology; GABA; GABA A; GABA-A Receptor Antagonists; Male; Mesocricetus; Mesocricetus auratus; Microinjections; Neuropeptide Y - antagonists & inhibitors; Neuropeptide Y - pharmacology; NPY; Receptors, GABA-A - metabolism; Regression Analysis; Suprachiasmatic Nucleus - metabolism; Suprachiasmatic Nucleus - physiology; Vertebrates: anatomy and physiology, studies on body, several organs or systems; GABA; GABA A; Circadian rhythm; NPY; Neuropeptide Y; Suprachiasmatic nucleus; Rodentia; Central nervous system; Biological rhythm; Hypothalamus; Vertebrata; Mammalia; Antagonist; Gabaergic receptor A; Hamster; Brain (vertebrata)
• ISSN: 0006-8993; 1872-6240
• DOI: 10.1016/0006-8993(95)00018-L

Microinjection of neuropeptide Y (NPY) into the suprachiasmatic nucleus of the hypothalamus (SCN) during the middle of the subjective day (i.e. circadian time 6) causes large phase advances in circadian rhythms. The present study demonstrates that microinjection of the γ-aminobutyric acid (GABA) antagonist, bicuculline, completely blocks NPY-induced phase advances. These data indicate that GABA A activity within the SCN may mediate the phase shifting effects of some stimuli on the circadian pacemaker.