[Comparative study of the electrocorticogram of several brain fields of dozing cats in a chronic experiment].

Peculatities of background electrical activity of some projection regions, the I somatosensory (field 53), and I and II auditory (fields 22 and 52, respectively), visual (field 17) and associative cortex (field 5), were studied in chronic experiments, performed on unanesthetized dozy cats. In transient periods, from vigil to sleep and vice versa, the maximal distinctions in slow-wave activity were detected between the regions under recording. They consisted in dissimilarities of spindle activity and low crosscorrelation coefficients (0.21 +/- 0.04). The synchrony of the potentials of different cortical regions increased and the crosscorrelation coefficients grew from 0.4 +/- 18 as sleep deepened. The functional reorganization of thalamic pacemaker mechanisms is supposed to take place with changes in the sleep depth. No distinctions in desynchronization were observed in different projective cortical fields because of the expressive orientation reflex. Only after the orientation reaction was suppressed and after application of the stimuli of adequate strength it was possible to reveal specific peculiarities of the projective field electrical reaction. Availability of definite conditions is emphasized for developing specific signs of the projective field electrical reaction.