Electrocorticogram in rats loaded with SART stress (repeated cold stress).
The electrocorticogram (ECoG) in a SART (specific alternation of rhythm in temperature)-stressed (repeatedly cold-stressed) rat, which is regarded as an experimental model for clinical vagotonic-type dysautonomia, was investigated in the present study by the power spectral technique. 1) Analysis of ECoG in SART-stressed rats during the resting-arousal state indicated a decrease in total power and a decrease in relative power in the delta band, and also an increase in relative power in the theta, alpha and beta bands. 2) In the slow-wave sleeping state, the ECoG of SART-stressed rats indicated a marked increase in total power, an increase in the delta band and decreases in theta, alpha and beta bands. 3) Electric stimulation of the posterior-hypothalamic area evoked alterations of ECoG similar to those caused by SART stress. ECoG response to electric stimulation in SART-stressed rats was less than that in unstressed rats. 4) Lesioning of the posterior-hypothalamic areas prevented SART stress-induced ECoG alterations. SART-stressed rats thus appear to be at a higher consciousness level on awakening but to sleep more soundly. They seem to exhibit greater fluctuation in brain activity than normal rats. There is also the possibility that the posterior-hypothalamic area is responsible to some degree for ECoG alterations in SART-stressed rats.
Hata
T
T
Department of Pharmacology, Faculty of Pharmacy, Kinki University, Osaka, Japan.
Nishimura
Y
Y
Kita
T
T
Kawabata
A
A
Itoh
E
E
D000818:Animals; D001143:Arousal; D003080:Cold Temperature; D004558:Electric Stimulation; D004569:Electroencephalography; D007034:Hypothalamus, Posterior / Q000503:physiopathology; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D012890:Sleep / Q000502:physiology; D013312:Stress, Physiological / Q000503:physiopathology*