Title: Neuronal activity in the association cortex of the cat during sleep, wakefulness and anesthesia
Abstract: Spontaneous activity of single neurons was recorded extracellularly from the association cortex (middle suprasylvian gyrus) of chronically prepared cats. The changes in neuronal firings were studied during sleep, wakefulness and pentobarbital (Nembutal) anesthesia. With behavioral shifts of the cat from wakefulness to slow wave sleep, 85.3% of the units decreased and 14.7% increased their firing rates. In REM (paradoxical) sleep, 94.8% of the units showed their highest firing rates. The activity levels, in terms of discharge rates of neurons, during pentobarbital anesthesia were by no means comparable to any states of natural sleep and wakefulness. The activity level during anesthesia ranged from 30% to 50% of the level found during slow wave sleep. More frequent interpositions of long silent periods in the spike trains were observed during anesthesia. However, there was no significant difference in firing patterns of the neurons between slow wave sleep and anesthesia. The neurons then fired irregularly and clustering predominated. The average values of the coefficient of variation, which estimates the degree of irregularity in the interspike intervals, were 1.52 and 1.50 in slow wave sleep and anesthesia, respectively, whereas they were 1.09 and 1.11 in REM sleep and behavioral arousal, respectively. During slow wave sleep and pentobarbital anesthesia, a high correlation was observed in the temporal patterns of firing of two neighboring cells recorded simultaneously. The probability of correlated firing was high with increased concurrent appearance of long silent periods in the neuronal pair. With a shift from sleep to wakefulness, correlation of silent periods between units was reduced and there was decreased probability of correlated firings. In arousal and REM sleep, the neuronal pairs discharged quite independently and the temporal patterns showed minimal correlation. The probability of correlated firings then fell to chance levels.
Publication Year: 1973
Publication Date: 1973-05-01
Language: en
Type: article
Indexed In: ['crossref', 'pubmed']
Access and Citation
Cited By Count: 51
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