Richard B. Yules

The effect of ethyl alcohol on man's electroencephalographic sleep cycle

Abstract This study indicates that 1 g of ethyl alcohol per kg of body weight administered before sleep exerts a systematic effect on EEG sleep patterns. In three human subjects over 13 consecutive nights (4 control, 5 alcohol, and 4 recovery nights), the most consistent pattern of change from night to night was seen in stage I REM. On the first night of alcohol the mean REM time dropped from the mean control value and over the next four consecutive nights on ethyl alcohol increased steadily to a peak value on the fifth night of alcohol. In four recovery nights REM time dropped back to control levels. This change in REM occurs in the first half of the night, when CSF alcohol levels are at their maximum concentration, and during the second half of the night. Latency or time to the first REM is constant in control and post-alcohol nights but varies unsystematically during nights of alcohol administration. Stages III and IV remain constant while stage II “absorbs” the shifts demonstrated in stage I.

Reticular formation control of vestibular system

Abstract In seventeen encephale isole cats, horizontal nystagmus elicited by electrical stimulation of the lateral vestibular nucleus was found to be modulated by stimulation of the mesencephalic reticular formation at the stereotaxic plane A-O. Four discrete effects were seen: with medial superior stimulation the contralateral vestibular complex was inhibited; medial inferior placements caused a facilitation of the contralateral nucleus; placements slightly lateral to the above produced inhibition of the ipsilateral complex; and lateral placements ventral to the lateral lemniscus produced a facilitation of the ipsilateral vestibular nucleus. In view of the dense fiber pathways to and from the cerebellum in this area and the connections of the cerebellum with the vestibular complex, it is possible that this effect might be mediated in part via the cerebellum and in part via the reticular formation.

The relationship of nystagmus to lateral vestibular nucleus stimulation

Abstract Electrical stimulation of the lateral vestibular nucleus was employed to elicit nystagmus in twenty-one acute cat preparations. Low intensity (2 v; 0.05 mamp) of 5-sec duration produced nystagmus with the fast component toward the side of stimulation; frequencies between 200 and 400 cycle/sec were most effective. Medium strength stimuli (9 v; 0.5 mamp) produced ocular tremor during stimulation and an afternystagmus in the same direction. Intense stimuli (15 v; 0.8 mamp) produced a reversal of afternystagmus, following the same response elicited with medium strength stimuli. Prolonging low-intensity stimulation time above 5 sec could simulate stimulations at higher intensities. The nystagmus response elicited by medium strength stimuli remained reproducible and constant over several hours.

The effect of ethyl alcohol on electroencephalographic sleep cycles in cats

EEGs taken from four sleeping cats for three control and four alcohol consecutive nights show that if 1 gm ethanol/kg body weight is administered 15 min. prior to sleep, Stage 1 REM time decreases from control values the first two alcohol nights but returns to control levels on the third and fourth alcohol nights. This pattern of change in REM time is the same as that found in humans. The REM time pattern is effected by a change in length rather than in numbers of REM periods. These data support the use of cats in establishing a mechanism for REM sleep which can be extrapolated to humans.

Physiology of the lateral vestibular nucleus

Abstract Simultaneous bilateral stimulation of the lateral vestibular nucleus in cats demonstrated that nystagmus evoked from each nucleus could be algebraically summated. This precise interaction was destroyed by labyrinthectomy which produced a resting nystagmus contralateral to the lesion. Resting nystagmus could be potentiated or inhibited by stimulating the appropriate nucleus. Atropine eliminated and amphetamine potentiated resting and elicited nystagmus. These data suggest a resting labyrinthine discharge which is necessary for vestibular stability in the intact animal and which enters the ipsilateral vestibular nucleus from which projections—possibly via the reticular formation—inhibit the contralateral lateral vestibular nucleus.

An implanted electrode for recording both rapid eye movements and muscle tone during sleep

Abstract A single electrode pair which permits recording of both cephalic muscle tone and rapid eye movements is described. Use of this method for recording channels, a animals provides the use of fewer recording channels, a method for accurately monitoring the REM state, and an easy means of comparing rapid eye movements with cephalic muscle tone.