Pavlov's sleep theory under a new light

EEG and behavioral effects of gamma-hydroxybutyrate in the rabbit

The effects of gamma-hydroxybutyrate (GHB) upon sleep wakefulness patterns and quantified nuchal muscle activity were examined in the rabbit in a dose-response paradigm (25-1,000 mg/kg). Relative to control (saline) values, there was no facilitation of sleep onset or epileptogenic activity at any of the dosages studied. However, at the higher GHB concentrations, slow wave sleep and tonic muscle activity were enhanced and a high amplitude, slow activity was superimposed on background EEG patterns. The highest concentration of GHB (1,000 mg/kg) was associated with depression of motor activity. An enhancement of paradoxical sleep observed at lower GHB levels in other species occurred in attenuated form in the rabbit. The results indicate dose-related effects on both sleep and motor activation in the rabbit, but the absence of seizure activity for the concentrations of GHB studied.

Factors in cerebrospinal fluid from goats that affect sleep and activity in rats

1. Intraventricular infusion in the rat of 0.1 ml. cerebrospinal fluid (c.s.f.) from sleep-deprived goats increases the duration of sleep (measured by e.e.g.) and decreases locomotor activity (measured photo-electrically) for at least 6 hr subsequent to the infusion. Subarachnoid infusions are ineffective.2. C.s.f. from control and sleep-deprived goats was fractionated by ultrafiltration through molecular sieves. The sleep-promoting Factor S is found in the low molecular weight fraction (mol. wt. < 500) of c.s.f. from sleep-deprived but not from control goats.3. The concentration of Factor S in c.s.f. increases progressively during the first 48 hr of sleep deprivation.4. The sleep promoting effects of Factor S cannot be duplicated by serotonin, 4-OH-butyrate, butyrolactone, GABA (gamma-amino butyric acid), glutamic acid or 3',5'-cyclic AMP when these substances are added to control fluids in concentrations up to 10 times greater than those found in normal c.s.f.5. Intraventricular or subarchnoid infusion in the rat of 0.1 ml. proteinfree c.s.f. containing molecules in the mol. wt. range of 500-10,000 at 10-30 x normal concentration causes hyperactivity which persists for several days and nights following the infusion. The excitatory material, probably a peptide, is present in c.s.f. from both control and sleep-deprived goats.6. The properties of Factor S suggest that it may play a role in the normal regulation of sleep and wakefulness.