[Dynamics of evoked potentials in cortical projection structures during a retarded instrumental defense reflex in dogs].

Evoked potentials (EP) in the somatosensory and auditory cortical areas were studied in four dogs against the background of a retarded defensive instrumental conditioned reflex to clicks. Four phases of the reflex were singled out by the changes in the structure of EP late components (LC) in the two projection zones. The most complex LC changes in the form of intensified negative components and the appearance of additional negative LC are recorded in response to the first click of the series and to the one followed by the conditioned motor reaction (CMR). Against the background of CMR delay, the EPs increased, while during the CMR, they decreased, owing to the diminished negative components, while the positive components were preserved and sometimes intensified. An assumption has been made that cortical projection structures of paired stimuli function in one and the same regime.