SPECTRAL CHARACTERISTICS OF RABBITS BRAIN ELECTRICAL-ACTIVITY AT THE DOMINANT OF THIRST

Dominant of thirst was elaborated in water-deprived rabbits by sound stimuli. One judged about the formation of the dominant by a regular appearance of the swallowing or chewing reactions in response to testing stimulations. Spectral analysis of the brain electrical activity revealed a generalized lowering of the spectral power of the potentials of the studied cortical and subcortical areas all over the analysed frequency range. The paraventricular nucleus, the lateral preoptic and anterior hypothalamic areas, in spectrograms of which an increase of extimations in the slow frequency range took place, were an exception. Analysis of the electrical activity recorded at different moments of the dominant manifestation (the tonic state of dominant and that immediately before the summation movement) showed that to each of these dominant states corresponded an appropriate maximum in the theta-frequency range, probably reflecting different levels of motivational-emotional excitation.