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

Dominant of thirst was elaborated in water-deprived rabbits by sound s timuli. One judged about the formation of the dominant by a regular ap pearance of the swallowing or chewing reactions in response to testing stimulations. Spectral analysis of the brain electrical activity reve aled a generalized lowering of the spectral power of the potentials of the studied cortical and subcortical areas all over the analysed freq uency range. The paraventricular nucleus, the lateral preoptic and ant erior hypothalamic areas, in spectrograms of which an increase of exti mations in the slow frequency range took place, were an exception. Ana lysis of the electrical activity recorded at different moments of the dominant manifestation (the tonic state of dominant and that immediate ly before the summation movement) showed that to each of these dominan t states corresponded an appropriate maximum in the theta-frequency ra nge, probably reflecting different levels of motivational-emotional ex citation.