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CHANGE OF PLASMA CORTICOSTERONE DURING SLEEP IN CATS
Author(s) -
TAKAHASHI Saburo,
HONDA Yutaka,
TAKAHASHI Kiyohisa,
OKUMA Teruo
Publication year - 1968
Publication title -
psychiatry and clinical neurosciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.609
H-Index - 74
eISSN - 1440-1819
pISSN - 1323-1316
DOI - 10.1111/j.1440-1819.1968.tb01433.x
Subject(s) - corticosterone , sleep deprivation , sleep (system call) , endocrinology , medicine , sleep stages , rapid eye movement sleep , circadian rhythm , electroencephalography , psychology , anesthesia , cats , polysomnography , hormone , neuroscience , computer science , operating system
Summary The relationship between the course and depth of sleep and pituitary‐adrenocortical activities was studied using adult cats. Metal electrodes were fixed on the skull and in the dorsal hippocampus for recording EEG. A serial collection of 2 ml of blood was performed at 15 minute intervals using a cardiac polyethylene catheter during sleep of the animal without anesthesia or restraint. Polygraphic recordings of EEG, ECG, EMG and eye movement were made simultaneously to determine the depth of sleep, which were classified into 4 stages of A, S‐1, S‐2 and S‐A stages. Plasma corticosterone was determined using a fluorometric technique. Two conditions were studied; one during natural sleep without previous sleep deprivation, and the other following 24 hours of sleep deprivation using the pool method. The following results were obtained: 1. Without preceding sleep deprivation, the animal showed mostly light sleep stages. The deep sleep and paradoxical sleep stages were only rarely observed. The plasma corticosterone level did not show marked changes during the experiments. 2. After 24 hours of sleep deprivation, the plasma corticosterone level was significantly low prior to the initiation of sleep, and rose significantly soon after the onset of sleep. The plasma corticosterone levels, in general, were also lower after sleep deprivation as compared to the experiments without sleep deprivation. 3. After sleep deprivation, plasma corticosterone values showed significant fluctuations in a cyclic pattern, roughly parallel to the sleep cycles. But no significant correlation between the values of corticosterone and each sleep stage was confirmed. 4. A tendency for the level of plasma corticosterone to decrease was observed frequently during the periods of S‐A stage. 5. The plasma corticosterone peaks tended to appear frequently at 5 to 14 minutes after the initiation of the preceding paradoxical sleep, or 10 to 29 minutes prior to the onset of the subsequent paradoxical sleep.