Ontogenetic analysis of the theta rhythm during paradoxical sleep in rats]

In the rat, an ontogenetic study of theta rhythm during paradoxical sleep shows a clear evolution between the 14th and the 30th postnatal day. During this period, its mean frequency increases from 5 to 7 cycles per second, and its spectrum shows significant changes. These parameters (mean frequency and spectral components) of the theta rhythm could be a useful index of brain maturation in the rat.     

Statistical relationship between "slow-wave sleep" and "paradoxical sleep" in rats]

In the Rat, statistical analysis of slow sleep (SS) and paradoxical sleep (PS) episodes disclosed two significant (p less than 0,01) positive correlations: (1) Over a four-hour period, the mean duration of PS episodes was correlated to the mean of the just preceding "light" SS episodes; (2) On the contrary, from cycle to cycle of sleep-wakefulness, the duration of each PS episode was correlated to that of the "light" SS episode of the next cycle.     

Excitability changes during paradoxical sleep in the rat

Résumé Le passage de la phase de sommeil avec ondes lentes à la phase ?paradoxale? et souvent aussi du sommeil paradoxal à l'éveil, sont accompagnés chez le rat d'un commencement ou d'une accentuation de l'activité dite ?spindling? dans l'écorce. Des changements phasiques de la fréquence des ondes ϑ dans l'hippocampe se produisirent pendant les périodes paradoxales. Nous n'avons pas remarqué de corrélations entre ces phénomènes.

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This work was supported in part by the US Public Health Service (grant NB-01883) and in part by the US Air Force Office of Scientific Research (grant AF-AFOSR 246-63).     

Cholinergic actions related to paradoxical sleep induction in the mesencephalic cat

Zusammenfassung In der auf der präcolliculären Höhe dezerbrierten Katze verursacht Physostigmin oder Pilocarpin den sogenannten paradoxen Schlaf. Atropin hemmt diese Einwirkung des Physostigmins.     

Tele-encephalic versus cerebellar control upon ponto-geniculo-occipital waves during paradoxical sleep in the cat

Summary Studying the effects that removal of the cerebellum and the frontal lobes had upon the phasic activities (PGO waves) of paradoxical sleep in the cat, it is shown that in this phase of the sleep-wakefulness cycle the cerebellum exerts an inhibitory action upon the amplitude of the GPO, while the frontal lobes influences the pattern of their discharges.This work was supported by Centro Nacional Ramon y Cajal de la Seguridad Social, Madrid, Spain.Acknowledgment. I am very grateful to Miss.M. Azuara for her technical assistance.     

Tele-encephalic versus cerebellar control upon ponto-geniculo-occipital waves during paradoxical sleep in the cat.

Studying the effects that removal of the cerebellum and the frontal lobes had upon the phasic activities (PGO waves) of paradoxical sleep in the cat, it is shown that in this phase of the sleep-wakefulness cycle the cerebellum exerts an inhibitory action upon the amplitude of the GPO, while the frontal lobes influences the pattern of their discharges.     

Neuronal activity specific to paradoxical sleep in the bulbar reticular formation in the unrestrained cat]

Single units were recorded in the bulbar reticular formation (BRF) of unrestrained, freely behaving Cats. In the ventromedial part of the BRF (n. reticularis magnocellularis, Mc) corresponding to the "bulbar inhibitory center", we have found a cluster of cells showing tonic activation highly selective to paradoxical sleep (PS). Furthermore, we have confirmed the presence of the same type of cells in the dorsomedial part of the BRF which corresponds to the medial part of the n. reticularis parvocellularis (Pc). The functional significance of these two groups of cells is discussed in terms of the postural atonia and the atonia of jaw closer muscles observed during PS.     

Phasic hippocampal activity during paradoxical sleep in the rat: selective suppression after diazepam administration

Summary The effects of diazepam on tonic (T) and phasic (P) components of the paradoxical-sleep hippocampal theta rhythm were studied in the rat. Results show that diazepam, a benzodiazepine analogue known to interfere with the putative neurotransmitter -aminobutyric acid (GABA) in the mammalian central nervous system, selectively abolishes P. They confirm previous data according to which sedative/anaesthetic drugs cause, an apparent dissociation of T and P of the paradoxical-sleep hippocampal theta rhythm. Moreover, they suggest a possible involvement of GABA in the neurochemical mechanisms underlying P in the rat.     

The influence of deprivation of paradoxical sleep on glycogen content in various brain structures of the cat

Zusammenfassung Nach selektiver Deprivation des paradoxalen Schlafes wurde der Spiegel des freien und gebundenen Glykogens in kortikalen und subkortikalen Hirnstrukturen der Katze bestimmt. Es wurde eine Intensitätskorrelation zwischen der paradoxalen Phasenaktivität einiger Strukturen und deren Veränderung der Glykogenfraktionen festgestellt. Der Gesamtglykogengehalt zeigt eine signifikante Senkung in Pons, Caudatus und Thalamus.     

Persistence of paradoxical sleep in the cat after destruction of the pontine gagantocellular tegmental field with kainic acid]

The pontine gigantocellular tegmental field (FTG) does not play any role in paradoxical sleep (PS) since the destruction of the cell bodies of the FTG with ka?nic acid does not alter PS in the Cat. Elimination of PS following electrolytic destruction of the ventrolateral pontine reticular formation can be explained by lesions of fibers connecting the region of the locus caeruleus and the bulbar reticular formation.     

Effects of bilateral dorsolateral pontine tegmentum lesions on hippocampus theta rhythm during paradoxical sleep in the rat]

Electrolytic lesions of the dorsolateral pontine tegmentum aimed at the locus coeruleus (LC) were performed bilaterally in 13 chronically implanted Rats. Following lesions, transient alterations of characteristic components of theta rhythm appeared. No shortening of duration of paradoxical sleep (PS) was observed. These results do not support the hypothesis that neurons of LC are directly involved in the production of theta rhythm during PS; moreover they seem not to be necessary to the normal appearance of this state of sleep.