QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

HOME  |   SEARCH  |   ARCHIVE  |   SUBSCRIBE  |   CONTACT  |   HELP

The Journal of Neuroscience, April 30, 2008, 28(18):4649-4660; doi:10.1523/JNEUROSCI.0334-08.2008

This Article Full Text Full Text (PDF) Submit an eLetter Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Google Scholar Articles by Burgess, C. Articles by Peever, J. PubMed PubMed Citation Articles by Burgess, C. Articles by Peever, J.

 Previous Article  |  Next Article 

Behavioral/Systems/Cognitive
An Endogenous Glutamatergic Drive onto Somatic Motoneurons Contributes to the Stereotypical Pattern of Muscle Tone across the Sleep–Wake Cycle

Christian Burgess,¹ Diane Lai,³ Jerome Siegel,³ and John Peever^1,2

Departments of ¹Cell and Systems Biology and ²Physiology, Systems Neurobiology Laboratory, University of Toronto, Toronto, Ontario, Canada M5S 3G5, and ³Neurobiology Research, Departments of Psychiatry and Biobehavioral Sciences, University of California at Los Angeles, Los Angeles, California 90095

Correspondence should be addressed to Dr. John Peever, Department of Cell and Systems Biology, University of Toronto, 25 Harbord Street, Toronto, Ontario, Canada M5S 3G5. Email: john.peever{at}utoronto.ca

Skeletal muscle tone is modulated in a stereotypical pattern across the sleep–wake cycle. Abnormalities in this modulation contribute to most of the major sleep disorders; therefore, characterizing the neurochemical substrate responsible for transmitting a sleep–wake drive to somatic motoneurons needs to be determined. Glutamate is an excitatory neurotransmitter that modulates motoneuron excitability; however, its role in regulating motoneuron excitability and muscle tone during natural sleep–wake behaviors is unknown. Therefore, we used reverse-microdialysis, electrophysiology, pharmacological, and histological methods to determine how changes in glutamatergic neurotransmission within the trigeminal motor pool contribute to the sleep–wake pattern of masseter muscle tone in behaving rats. We found that blockade of non-NMDA and NMDA glutamate receptors (via CNQX and D-AP-5) on trigeminal motoneurons reduced waking masseter tone to sleeping levels, indicating that masseter tone is maximal during alert waking because motoneurons are activated by an endogenous glutamatergic drive. This wake-related drive is switched off in non-rapid eye movement (NREM) sleep, and this contributes to the suppression of muscle tone during this state. We also show that a functional glutamatergic drive generates the muscle twitches that characterize phasic rapid-eye movement (REM) sleep. However, loss of a waking glutamatergic drive is not sufficient for triggering the motor atonia that characterizes REM sleep because potent activation of either AMPA or NMDA receptors on trigeminal motoneurons was unable to reverse REM atonia. We conclude that an endogenous glutamatergic drive onto somatic motoneurons contributes to the stereotypical pattern of muscle tone during wakefulness, NREM sleep, and phasic REM sleep but not during tonic REM sleep.

Key words: sleep; REM atonia; glutamatergic neurotransmission; trigeminal; motoneuron; NREM sleep

---

Received Oct. 2, 2007; accepted March 18, 2008.

Correspondence should be addressed to Dr. John Peever, Department of Cell and Systems Biology, University of Toronto, 25 Harbord Street, Toronto, Ontario, Canada M5S 3G5. Email: john.peever{at}utoronto.ca

This article has been cited by other articles:

				H. W. Steenland, H. Liu, and R. L. Horner Endogenous Glutamatergic Control of Rhythmically Active Mammalian Respiratory Motoneurons In Vivo J. Neurosci., July 2, 2008; 28(27): 6826 - 6835. [Abstract] [Full Text] [PDF]

Home  |   Search  |   Archive  |   Subscribe  |   Contact  |   Help