6. Conclusions and new hypothesis
During SWS, the noradrenergic neurons of the LC would be inhibited by
GABA-ergic neurons located in the lateral preoptic area. At the entrance
and during PS, a second population of GABA-ergic neurons located in the
periaqueductal gray or the dorsal paragigantocellular nucleus would be
responsible for the complete cessation of the noradrenergic neurons of
the LC during this sleep state. The cranial motoneurons would be inhibited
by glycinergic neurons of the parvocellular nucleus and those of the spinal
cord by glycinergic neurons from the gigantocellular ventral nucleus and
glycinergic interneurons of the intermediate zone of the spinal cord.
ACKNOWLEDGMENTS
This work was supported by INSERM (U480), CNRS (ERS 5645), Université
Claude Bernard Lyon I and the 1996 ESRS-Synthélabo European Research
Grant. The authors wish to thank C. Guillemort (GFG Co, Pierre-Bénite)
for his help in designing the head-restraining system.
Abbreviations used in the text
- CNS Central Nervous System
- CTb cholera toxin B subunit
- DRN dorsal raphe nucleus
- EEG Electroencephalogram
- EMG Electromyogram
- GABA Gamma amino-butyric acid
- GAD glutamate decarboxylase
- Gia nucleus gigantocellular alpha
- GiV nucleus gigantocellular ventral
- GLY glycine
- IPSP Inhibitory post-synaptic potential
- LC Locus coeruleus
- PS Paradoxical sleep
- SWS Slow wave sleep
- W Wakefulness
|