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EFFECTS OF HYPOTHERMIA ON THE ELECTRICAL ACTIVITY OF THE BRAIN, ESPECIALLY ON THE THALAMO‐CORTICAL CIRCUITS
Author(s) -
Yoshii Naosaburo,
Koyasu Yoshihiko,
Okazalci Kinichi,
Hasegawa Yoshiharu
Publication year - 1955
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.1440-1819.1955.tb00722.x
Subject(s) - hypothermia , thalamus , barbiturate , cats , anesthesia , electrophysiology , medicine , electroencephalography , cerebral cortex , cortex (anatomy) , neuroscience , psychology
Summary 1. Changes in electrorortical activity of cats and dogs during hypothermia were studied. 2. The frequency of background potentials changed almost linearly with temperature, though there was appreciable lag of the increase in the frequency during rewarming, whereas the wave frequency of spontaneous barbiturate bursts was fairly preserved in the face of moderate hypothermia. 3 . Repetitive after‐discharges elicited by single volley applied to the thalamus could be seen during cooling of the animal until they disappeared a little before or shortly after the beginning of rewarming at a temperature of about 20°C., and they reappeared when the animal reached a temperature of about 30°C. during rewarming. 4. Evoked potentials as picked up from the cerebral cortex as primary response to thalamic stimulation persisted even in the extreme of hypothermia in these experiments. 5. The behavior of both the thalamo‐cortical circuits and brain stem activating system against cooling and rewarming is discussed, and it is concluded from these results that the oligosynaptic pathways are more resistant to cold and anesthesia than the multiysnaptic systems.