Paradoxical Sleep - A Study of its Nature and Mechanisms
Michel Jouvet
Progress In Brain Research Vol. 18 Sleep Mechanisms 1965
Evidence of the duality of the states of sleep

(a) EEG and behavioural findings

(b) Phylogenetic findings

(c) Ontogenetic findings

(d) Functional findings

(e) Structural findings

Mechanisms of paradoxical sleep

(a) Producing P.S. as a reflex

(b) Results of deafferentations

(c) Role of the hypothalamus and pituitary

(d) Deprivation of P.S. in the pontile animal

(e) Effects of temperature on P.S. in the pontile animal

(f) Action of gamma-butyrolactone (G.B.L.)

(g) Osmolarity of the blood and paradoxical sleep


(a) Duality of the states of sleep

(b) Mechanisms underlying the appearance of P.S.

Summary and Conclusions



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Mechanisms of paradoxical sleep

(e) Effects of temperature on P.S. in the pontile animal

The poikilothermic pontile animal is subject to changes in the environmental temperature, so that the effects of hypothermia on P.S. can be readily studied. The fall in rectal temperature occurring when the animal is placed in a cold environment causes P.S. to disappear almost entirely. If, however, cooling is stopped and the rectal temperature remains stable, P.S. reappears periodically. Its duration is then in inverse proportion to the rectal temperature (Fig. 22). An increase in the duration of P.S. during hypothermia goes hand in hand with an increase in the length of the intervals between each episode of P.S., the proportion of the latter always remaining in the region of 10%. We have observed periods of P.S. lasting 25 min at a rectal temperature of 29°. At this temperature the animals exhibit generalized clonism of the head and limbs, even when they are returned to a warm environment. There is no real shivering, however. During phases of P.S. clonism disappears almost completely. If the animal is rewarmed so that the rectal temperature increases P.S. occurs more frequently and in animals whose temperature rises from 30° to 37° in 4 h the amount of sleep can increase to up to 35% of the total time.

In contrast, we have never observed P.S. at temperatures above 40.5. (This was the maximum temperature attempted, as hyperthermia has serious effects in pontile animals.)

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