Hypothalamic electrical activity that relates to the pulsatile release of luteinizing hormone exhibits diurnal variation in ovariectomized rats.
The multiunit activity (MUA) was recorded in the arcuate nucleus-median eminence region in freely moving ovariectomized rats maintained under controlled lighting conditions (lights on 05.00-19.00 h) over a period of 24 h. The MUA of each rat had been confirmed to exhibit characteristic increases (volleys) in association with pulses of luteinizing hormone. In 6 MUAs examined, the frequency of MUA volleys was significantly greater in the dark period than in the light period, suggesting a diurnal variation in the release of luteinizing hormone-releasing hormone in the ovariectomized rat.
Hiruma
H
H
Department of Physiology, Yokohama City University School of Medicine, Japan.
Nishihara
M
M
Kimura
F
F
D000818:Animals; D002940:Circadian Rhythm; D003624:Darkness; D004553:Electric Conductivity; D005260:Female; D007031:Hypothalamus / Q000502:physiology*; D008027:Light; D007986:Luteinizing Hormone / Q000097:blood / Q000378:metabolism*; D010052:Ovariectomy; D011863:Radioimmunoassay; D051381:Rats; D011919:Rats, Inbred Strains
D007986:Luteinizing Hormone