In an attempt to suppress paradoxical sleep (PS) an intracerebral injection of 6 0HDA was carried out on rat faetuses at a gestational age of 16-20 days. In these animals a delay in maturation occurred compared to controls, the only modification of sleep being observed however, related to the circadian rhythmn of PS. The possible reasons for this are discussed within the framework of a concept relating paradoxical sleep to cerebral maturation.

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PubMedDate not supplied

An automatic sleep classifier for laboratory rodents.

Two successive main steps are usually performed in automatic sleep classification: a) a periodic quantification of the EEG signal by a set of indices featuring each polygraphic epoch by a point in a multidimensional space, b) a stage decision to determine the cluster that includes the representative point for a given epoch (discriminant analysis). As solid state logic comparators simulate linear discriminant functions, this article describes an improved classifier for automatic sleep scoring in laboratory rodents. Four indices were found to be discriminant on both rats and mice: F(the energy in the EEG theta band relative to that in the delta band), Z(number of EEG zero-crossings), D(variability of the EEG amplitude) and M(integrated EMG). They are measured by analog techniques for 30 sec epochs from an EEG and an EMG lead per animal. At the end of each epoch, the logic results of their respective comparators serves as an input to a hardwired modifiable truthtable where a sleep stage decision is elaborated. The outputs of 4 multiplexed classifiers are controlled by microprocessor and may be used for chart or digital recordings on various peripherals. The overall agreement with visual scoring is more than 95% for both rats and mice.

Animals↗

PubMedDate not supplied

[Genetic study of paradoxical sleep in mice. Connection with coloration genes].

The study of Paradoxical Sleep (PS) from 94 male mice belonging to five inbred strains: C57BR/cdOrl (BR), BALB/cOrl (C), AKROrl, A/JOrl (A/J) and C57BL/6-c2J (B6-c2J), reciprocal F1 hybrids between BR and C strains and backcrosses between F1 hybrids and BR or C was carried out. The results showed that 1) night PS duration was independent from that of day PS; 2) C type of PS seemed to be dominant over BR type; 3) C type is linked to the albino gene; and 4) the albino gene, per se, is not involved in PS regulation. From these results a two locus model was elaborated. This model explains most of the results. The nature of such a genetic support was discussed.

Animals↗