SLEEP - Evidence that Neurons of the Sublaterodorsal Tegmental Nucleus Triggering Paradoxical (REM) Sleep Are Glutamatergic

VOLUME 34, ISSUE 04

GLUTAMATERGIC NEURONS INVOLVED IN REM SLEEP REGULATION
Evidence that Neurons of the Sublaterodorsal Tegmental Nucleus Triggering Paradoxical (REM) Sleep Are Glutamatergic

Olivier Clément, MSc¹^,²; Emilie Sapin, PhD¹^,²^,³^,⁴; Anne Bérod, PhD¹^,²^,⁵; Patrice Fort, PhD¹^,²; Pierre-Hervé Luppi, PhD¹^,²

¹Physiopathology of the Neuronal Network Responsible for the Sleep-Waking Cycle Team, CNRS UMR5292; INSERM U1028; Lyon Neuroscience Research Center, Lyon, F-69372, France ; ²Université Lyon 1, Université de Lyon, Lyon, F-69000, France ; ³INSERM U1042, Grenoble, F-38043, France ; ⁴Université de Grenoble, U 1042, Grenoble, F-38043, France ; ⁵CNRS, EAC5006, Pharmacologie et Imagerie de la Neurotransmission Sérotoninergique, Lyon, France

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Study Objectives:

To determine whether sublaterodorsal tegmental nucleus (SLD) neurons triggering paradoxical (REM) sleep (PS) are glutamatergic.

Design:

Three groups of rats were used: controls, rats deprived of PS for 72 h, and rats allowed to recover for 3 h after deprivation. Brain sections were processed for double labeling combining Fos immunohistochemistry and vesicular glutamate transporter 2 (vGLUT2) in situ hybridization.

Measurements and Results:

The number of single Fos+ and Fos/vGLUT2+ double-labeled neurons was counted for each experimental condition. A very large number of Fos+ neurons expressing vGLUT2 mRNA specifically after PS hypersomnia was counted in the SLD. These double-labeled cells accounted for 84% of the total number of Fos+ cells.

Conclusions:

This finding adds further evidence to the concept that PS-on neurons of the SLD generating PS are of small size and glutamatergic in nature. By means of their descending projections to medullary and/or spinal glycinergic/GABAergic premotoneurons, they may be especially important for the induction of muscle atonia during PS, a disturbed phenomenon in narcolepsy and REM sleep behavior disorder.

Citation:

Clément O; Sapin E; Bérod A; Fort P; Luppi PH. Evidence that neurons of the sublaterodorsal tegmental nucleus triggering paradoxical (REM) sleep are glutamatergic. SLEEP 2011;34(4):419-423.