Abstract
During the experiments observing the drug effects on the steady potential of various brain structures, the authors (1) found that the steady potentials of certain subcortical structures such as the hypothalamus and hippocampus were more sensitively altered by psychopharmacological agents than the EEG activity in the same areas. Although many attempts (2-4) have been made to explain the steady potential, its physiological significance has been still unknown. The authors have been interested in this electrical phenomenon from their belief that changes in the steady potential would indicate the CNS activity in some different way from EEG changes. In order to elucidate the correlation between a steady potential and EEG in the various states of activity of the brain, the more primitive brain structure seemed desirable to persue. The authors thus selected the olfactory bulb, because this structure showed a distinct afferent activity in response to olfactory stimulation and its excitatory as well as inhibitory states could be easily demonstrated. Ottoson (5, 6) has observed a slow potential elicited by odoriferous stimulation in the olfactory epithelium as well as in the olfactory bulb. Ottoson's slow potential is regarded as a DC potential change in this structure. The present study was conducted to ascertain the effects of drugs on the DC potential, slow potential and EEG activity of the olfactory bulb, in the hope of elucidating if any mutual correlations of these electrical phenomena exist.
