Chihiro Ohye

Cortical polarization and experimentally produced delta waves in the cat

Abstract 1. 1. Localized and diffuse delta activity induced, respectively, by acute lesions in the medial geniculate body (22 cats) and in the posterior hypothalamus (29 cats) were investigated using the midpontine pretrigeminal preparation. 2. 2. Both localized and diffuse delta waves were enhanced by application of surface negative polarizing current, and reduced by surface positive polarizing current. From these findings and those derived from the literature it was inferred that delta waves are chiefly surface positive potentials. 3. 3. The study of laminar distribution of delta waves within the cortex revealed two different potential distributions. The localized delta waves were larger at superficial than at deeper layers. The phase reversal occurred at about 1400 μ or less below the cortical surface. The diffuse delta waves were smaller at superficial than at deep layers. The phase reversed at 500 μ below the surface. This potential distribution of diffuse delta waves was closely correlated with that of the surface positive component of the primary response evoked by stimulation of the thalamic relay nucleus. 4. 4. Interaction between delta waves induced by posterior hypothalamic lesion and the surface positive component of the primary response showed that the amplitude of the positive component of the primary response was enhanced in the falling phase of a delta wave. 5. 5. Possible structures and synaptic events which might subserve the production of these delta waves were discussed.

Polygraphic study of the effects of sodium 4-hydroxybutyrate and 4-butyrolactone in man

Abstract Polygraphic observations were made after intravenous or intracarotid administration of sodium 4-hydroxy utyrate and 4-butyrolactone in man. At first theta bursts, then large continuous delta waves appeared in the EEG with increased EMG, accelerated respiration and heart rate. Consciousness was maintained. This was followed by irregular slow waves with reduced EMG, slow and stable respiration and heart rate, and a loss in consciousness. In 7 cases among 19, changes resembling paradoxical sleep were observed during this phase. The whole course of events was changed suddenly at two or three hr after the onset of injection. No disorientation or noticeable side effects were observed. When blood concentration of butyrate was measured and correlated with the polygraphic recordings, the continuous large slow wave stage corresponded to the peak of the blood concentration level while the irregular slow wave stage corresponded to the declining phase of the blood level curve. The effects of these compounds in producing continuous large slow waves without a disturbance of consciousness was emphasized.