R L Horner

Summary

Affiliation: University of Toronto
Country: Canada

Publications

  1. ncbi Effects of sleep-wake state on the genioglossus vs.diaphragm muscle response to CO(2) in rats
    Richard L Horner
    Department of Medicine, University of Toronto, Toronto, Canada M5S 1A8
    J Appl Physiol (1985) 92:878-87. 2002
  2. doi Neural control of the upper airway: integrative physiological mechanisms and relevance for sleep disordered breathing
    Richard L Horner
    Department of Medicine, University of Toronto, Toronto, Canada
    Compr Physiol 2:479-535. 2012
  3. doi Identification of the mechanism mediating genioglossus muscle suppression in REM sleep
    Kevin P Grace
    Department of Medicine, University of Toronto, Toronto, Canada
    Am J Respir Crit Care Med 187:311-9. 2013
  4. doi The tongue and its control by sleep state-dependent modulators
    R L Horner
    Department of Medicine and Department of Physiology, University of Toronto, Toronto, Ontario, Canada
    Arch Ital Biol 149:406-25. 2011
  5. ncbi Update in sleep and control of ventilation 2005
    Richard L Horner
    Department of Medicine and Physiology, University of Toronto, Sleep Research Laboratory of the Toronto Rehabilitation Institute, Toronto General Hospital of the University Health Network, Toronto, ON, Canada M5S 1A8
    Am J Respir Crit Care Med 173:827-32. 2006
  6. ncbi Update in sleep and control of ventilation 2006
    Richard L Horner
    Department of Medicine, University of Toronto, Toronto, Canada
    Am J Respir Crit Care Med 175:426-31. 2007
  7. ncbi Morphine-induced acetylcholine release at the hypoglossal motor nucleus: implications for opiate-induced respiratory suppression
    Richard L Horner
    Department of Medicine, University of Toronto, Toronto, Canada
    Sleep 30:551-2. 2007
  8. ncbi Control of genioglossus muscle by sleep state-dependent neuromodulators
    Richard L Horner
    University of Toronto, Department of Medicine
    Adv Exp Med Biol 605:262-7. 2008
  9. doi Update in sleep and control of ventilation 2007
    Richard L Horner
    Department of Medicine, University of Toronto, Toronto, Canada
    Am J Respir Crit Care Med 177:947-51. 2008
  10. doi Pathophysiology of obstructive sleep apnea
    Richard L Horner
    Department of Medicine, University of Toronto, Toronto, Ontario, Canada
    J Cardiopulm Rehabil Prev 28:289-98. 2008

Collaborators

Detail Information

Publications46

  1. ncbi Effects of sleep-wake state on the genioglossus vs.diaphragm muscle response to CO(2) in rats
    Richard L Horner
    Department of Medicine, University of Toronto, Toronto, Canada M5S 1A8
    J Appl Physiol (1985) 92:878-87. 2002
    ..4% vs. wakefulness). Such major suppression of GG activity in REM, even with significant respiratory stimulation, may explain why obstructive apneas are more common in REM sleep...
  2. doi Neural control of the upper airway: integrative physiological mechanisms and relevance for sleep disordered breathing
    Richard L Horner
    Department of Medicine, University of Toronto, Toronto, Canada
    Compr Physiol 2:479-535. 2012
    ....
  3. doi Identification of the mechanism mediating genioglossus muscle suppression in REM sleep
    Kevin P Grace
    Department of Medicine, University of Toronto, Toronto, Canada
    Am J Respir Crit Care Med 187:311-9. 2013
    ..However, blockade of that mechanism at cranial motor nuclei increases motor activity in all sleep-wake states, and least of all in REM sleep, arguing against it as a major mechanism of REM sleep pharyngeal motor inhibition...
  4. doi The tongue and its control by sleep state-dependent modulators
    R L Horner
    Department of Medicine and Department of Physiology, University of Toronto, Toronto, Ontario, Canada
    Arch Ital Biol 149:406-25. 2011
    ....
  5. ncbi Update in sleep and control of ventilation 2005
    Richard L Horner
    Department of Medicine and Physiology, University of Toronto, Sleep Research Laboratory of the Toronto Rehabilitation Institute, Toronto General Hospital of the University Health Network, Toronto, ON, Canada M5S 1A8
    Am J Respir Crit Care Med 173:827-32. 2006
  6. ncbi Update in sleep and control of ventilation 2006
    Richard L Horner
    Department of Medicine, University of Toronto, Toronto, Canada
    Am J Respir Crit Care Med 175:426-31. 2007
  7. ncbi Morphine-induced acetylcholine release at the hypoglossal motor nucleus: implications for opiate-induced respiratory suppression
    Richard L Horner
    Department of Medicine, University of Toronto, Toronto, Canada
    Sleep 30:551-2. 2007
  8. ncbi Control of genioglossus muscle by sleep state-dependent neuromodulators
    Richard L Horner
    University of Toronto, Department of Medicine
    Adv Exp Med Biol 605:262-7. 2008
    ..Knowledge of such mechanisms is relevant to identifying and developing new strategies to augment pharyngeal muscle activity in sleep, potentially as treatments for obstructive sleep apnea...
  9. doi Update in sleep and control of ventilation 2007
    Richard L Horner
    Department of Medicine, University of Toronto, Toronto, Canada
    Am J Respir Crit Care Med 177:947-51. 2008
  10. doi Pathophysiology of obstructive sleep apnea
    Richard L Horner
    Department of Medicine, University of Toronto, Toronto, Ontario, Canada
    J Cardiopulm Rehabil Prev 28:289-98. 2008
    ..Throughout this review, these mechanisms are discussed with an emphasis on understanding the physiology and pathophysiology of sleep-disordered breathing and obstructive sleep apnea...
  11. pmc Emerging principles and neural substrates underlying tonic sleep-state-dependent influences on respiratory motor activity
    Richard L Horner
    Department of Medicine, University of Toronto, Room 7308 Medical Sciences Building, 1 Kings College Circle, Toronto, Ontario M5S 1A8, Canada
    Philos Trans R Soc Lond B Biol Sci 364:2553-64. 2009
    ..In sleep, the excitatory inputs are withdrawn and GABA release into the brainstem is increased, thus decreasing respiratory motor tone and predisposing susceptible individuals to hypoventilation and obstructive sleep apnoea...
  12. doi Neuromodulation of hypoglossal motoneurons during sleep
    Richard L Horner
    Department of Medicine, Room 7308, Medical Sciences Building, University of Toronto, 1 Kings College Circle, Toronto, Ontario M5S IA8, Canada
    Respir Physiol Neurobiol 164:179-96. 2008
    ..New concepts on the control of hypoglossal motoneurons by sedative hypnotics are also discussed...
  13. ncbi Respiratory motor activity: influence of neuromodulators and implications for sleep disordered breathing
    Richard L Horner
    Department of Medicine, University of Toronto, 1 Kings College Circle, Toronto, ON M5S 1A8, Canada
    Can J Physiol Pharmacol 85:155-65. 2007
    ....
  14. pmc The neuropharmacology of upper airway motor control in the awake and asleep states: implications for obstructive sleep apnoea
    R L Horner
    Department of Medicine and Department of Physiology, University of Toronto, 1 Kings College Circle, Toronto, Ontario, Canada M5S 1A8
    Respir Res 2:286-94. 2001
    ....
  15. ncbi Sleep architecture in a canine model of obstructive sleep apnea
    R L Horner
    Department of Medicine, University of Toronto, Canada
    Sleep 21:847-58. 1998
    ..Rather, repeated sleep disruption due to the effects of repetitive apneas and hypoxia may lead to an increased REM sleep drive that manifests itself as a REM sleep rebound during recovery sleep after OSA...
  16. pmc The ventilatory response to arousal from sleep is not fully explained by differences in CO(2) levels between sleep and wakefulness
    R L Horner
    Departments of Medicine and Physiology, University of Toronto, Medical Sciences Building, 1 Kings College Circle, Toronto, Ontario, Canada, M5S 1A8
    J Physiol 534:881-90. 2001
    ..This result leads to important modifications of the physiological model currently used to explain the ventilatory consequences of arousal from sleep...
  17. ncbi Impact of brainstem sleep mechanisms on pharyngeal motor control
    R L Horner
    Room 6368, Departments of Medicine and Physiology, Medical Sciences Building, University of Toronto, 1 Kings College Circle, Toronto, Ont, Canada
    Respir Physiol 119:113-21. 2000
    ....
  18. ncbi Respiratory activation of the genioglossus muscle involves both non-NMDA and NMDA glutamate receptors at the hypoglossal motor nucleus in vivo
    H W Steenland
    Department of Medicine and Physiology, University of Toronto, Toronto, Ontario, Canada M5S 1A8
    Neuroscience 138:1407-24. 2006
    ..These results show that both NMDA and non-NMDA glutamate receptors at the hypoglossal motor nucleus are involved in transmission of the respiratory drive signal to genioglossus muscle in vivo...
  19. pmc Microdialysis perfusion of 5-HT into hypoglossal motor nucleus differentially modulates genioglossus activity across natural sleep-wake states in rats
    A Jelev
    Departments of Medicine and Physiology, University of Toronto, Toronto, Canada, M5S 1A8
    J Physiol 532:467-81. 2001
    ..This animal model using in vivo microdialysis of the caudal medulla will enable the determination of neural mechanisms underlying pharyngeal motor control in natural sleep...
  20. pmc Circadian rhythms and sleep have additive effects on respiration in the rat
    R Stephenson
    Department of Physiology, University of Toronto, Toronto, Ontario, Canada M5S 1A1
    J Physiol 536:225-35. 2001
    ..We conclude that the effects of circadian rhythms and sleep-wake state on respiration and metabolic rate are additive in the rat...
  21. ncbi 5-HT at hypoglossal motor nucleus and respiratory control of genioglossus muscle in anesthetized rats
    Sandeep Sood
    Department of Medicine, University of Toronto, Room 6368, Medical Sciences Building, 1 Kings College Circle, Toronto, Ont, Canada M5S 1A8
    Respir Physiol Neurobiol 138:205-21. 2003
    ..02). However, 5-HT increased respiratory-related GG activity at levels lower (1 mM) than those eliciting tonic GG activity (10-30 mM 5-HT). The results show that 5-HT at the HMN contributes to the respiratory control of GG muscle...
  22. doi State-dependent vs. central motor effects of ethanol on breathing
    Laura M Vecchio
    Department of Physiology, University of Toronto, Toronto, Ontario, Canada
    J Appl Physiol (1985) 108:387-400. 2010
    ....
  23. pmc Systemic vs. central administration of common hypnotics reveals opposing effects on genioglossus muscle activity in rats
    Eileen Park
    Department of Medicine, University of Toronto, Toronto, Canada
    Sleep 31:355-65. 2008
    ..We also determined effects on GG activity with local application to the hypoglossal motor nucleus (HMN)...
  24. ncbi Suppression of genioglossus muscle tone and activity during reflex hypercapnic stimulation by GABA(A) mechanisms at the hypoglossal motor nucleus in vivo
    X Liu
    Department of Medicine, University of Toronto, Toronto, M5S 1A8, Canada
    Neuroscience 116:249-59. 2003
    ..Recruitment of such mechanisms may contribute to the major suppression of genioglossus activity observed with and without CO(2) stimulation in behaviours such as rapid-eye-movement sleep...
  25. pmc Opioid receptor mechanisms at the hypoglossal motor pool and effects on tongue muscle activity in vivo
    Mohammad Hajiha
    Department of Medicine, University of Toronto, Toronto, Ontario, Canada
    J Physiol 587:2677-92. 2009
    ..The inhibitory effects of mu- and delta-opioid receptors at the HMN also indicate an influence of endogenous enkephalins and endorphins in respiratory motor control...
  26. ncbi Inhibition of serotonergic medullary raphe obscurus neurons suppresses genioglossus and diaphragm activities in anesthetized but not conscious rats
    Sandeep Sood
    Department of Medicine, Rm 6368, Medical Sciences Bldg, 1 Kings College Circle, University of Toronto, ON, Canada M5S 1A8
    J Appl Physiol 100:1807-21. 2006
    ..This result has implications for pharmacological strategies aiming to manipulate raphe neurons and endogenous serotonin in obstructive sleep apnea...
  27. pmc Role of inhibitory amino acids in control of hypoglossal motor outflow to genioglossus muscle in naturally sleeping rats
    Janna L Morrison
    Departments of Medicine and Physiology, University of Toronto, Toronto, Canada M5S 1A8
    J Physiol 552:975-91. 2003
    ....
  28. ncbi Selected Contribution: Regulation of sleep-wake states in response to intermittent hypoxic stimuli applied only in sleep
    H Hamrahi
    Departments of Medicine and Physiology, University of Toronto, Toronto, Ontario, Canada M5S 1A8
    J Appl Physiol 90:2490-501. 2001
    ..This study is the first to determine the independent effects of sleep-related hypoxia on sleep regulation that approximates OSA before and after treatment...
  29. pmc GABAA receptor antagonism at the hypoglossal motor nucleus increases genioglossus muscle activity in NREM but not REM sleep
    Janna L Morrison
    Department of Medicine, University of Toronto, Canada M5S 1A8
    J Physiol 548:569-83. 2003
    ....
  30. pmc Modulation of genioglossus muscle activity across sleep-wake states by histamine at the hypoglossal motor pool
    Timothy Bastedo
    Department of Medicine, University of Toronto, Toronto, ON, Canada
    Sleep 32:1313-24. 2009
    ....
  31. ncbi Endogenous excitatory drive modulating respiratory muscle activity across sleep-wake states
    Erin Chan
    Department of Medicine, University of Toronto, Toronto, Ontario, Canada
    Am J Respir Crit Care Med 174:1264-73. 2006
    ..However, a neurotransmitter substrate mediating respiratory muscle activation across sleep-wake states has not been identified...
  32. doi Endogenous glutamatergic control of rhythmically active mammalian respiratory motoneurons in vivo
    Hendrik W Steenland
    Department of Medicine, University of Toronto, Toronto, Ontario, Canada
    J Neurosci 28:6826-35. 2008
    ..These data do not refute previous identification of a glutamatergic (mostly non-NMDA receptor activating) respiratory drive to hypoglossal motoneurons, but this mechanism is more prominent in anesthetized or in vitro preparations...
  33. ncbi On-line detection of sleep-wake states and application to produce intermittent hypoxia only in sleep in rats
    H Hamrahi
    Department of Medicine, University of Toronto, Toronto, Ontario, Canada M5S 1A8
    J Appl Physiol 90:2130-40. 2001
    ....
  34. ncbi Pentobarbital sedation increases genioglossus respiratory activity in sleeping rats
    Magdy Younes
    Department of Medicine, University of Toronto, ON, Canada
    Sleep 30:478-88. 2007
    ..Intermittently, inspired CO2 was increased gradually until arousal occurred...
  35. ncbi Glycine at hypoglossal motor nucleus: genioglossus activity, CO(2) responses, and the additive effects of GABA
    Janna L Morrison
    Departments of Medicine and Physiology, University of Toronto, Toronto, Ontario, Canada M5S 1A8
    J Appl Physiol 93:1786-96. 2002
    ..It remains to be determined whether the recruitment of such glycine and GABA mechanisms explains the periods of major GG suppression in behaviors such as rapid eye movement sleep...
  36. ncbi Sleep as a teaching tool for integrating respiratory physiology and motor control
    S R Thompson
    Department of Physiology, University of Toronto, Toronto, Ontario, M5S 1A8, Canada
    Adv Physiol Educ 25:101-16. 2001
    ..In this paper, examples of how sleep influences motor control and the respiratory system will illustrate these points. These considerations also highlight some important gaps in traditional teaching of respiratory physiology...
  37. ncbi Role of endogenous serotonin in modulating genioglossus muscle activity in awake and sleeping rats
    Sandeep Sood
    Department of Medicine, University of Toronto, Toronto, Canada
    Am J Respir Crit Care Med 172:1338-47. 2005
    ....
  38. ncbi The effect of time of day on apnoea index in the sleeping rat
    Richard Stephenson
    Departments of Zoology, University of Toronto, Ramsay Wright Building, 25 Harbord Street, Toronto, Ont, Canada M5S 3G5
    Respir Physiol Neurobiol 154:351-5. 2006
    ..We conclude that the circadian timing system has no effect on apnoea index during NREM sleep in the rat, but it may influence the propensity for post-sigh apnoea during REM sleep...
  39. pmc Caffeine in the neonatal period induces long-lasting changes in sleep and breathing in adult rats
    Gaspard Montandon
    Departments of Medicine and Physiology, Faculty of Medicine, University of Toronto, Ontario, Canada
    J Physiol 587:5493-507. 2009
    ....
  40. doi PreBotzinger complex neurokinin-1 receptor-expressing neurons mediate opioid-induced respiratory depression
    Gaspard Montandon
    Department of Medicine and Physiology, University of Toronto, Toronto, Ontario M5S 1A8, Canada
    J Neurosci 31:1292-301. 2011
    ..In summary, neurokinin-1 receptor-expressing preBötzinger complex neurons constitute the critical site mediating opioid-induced respiratory rate depression, and the key therapeutic target for its prevention or reversal...
  41. pmc Opposing muscarinic and nicotinic modulation of hypoglossal motor output to genioglossus muscle in rats in vivo
    Xia Liu
    Department of Medicine, University of Toronto, Ontario, Canada, M5S 1A8
    J Physiol 565:965-80. 2005
    ..The results suggest that acetylcholine has mixed effects at the HMN with muscarinic-mediated GG suppression masking nicotinic excitation...
  42. ncbi Genioglossus muscle activity and serotonergic modulation of hypoglossal motor output in obese Zucker rats
    Sandeep Sood
    Department of Medicine, Rm 6368, Medical Sciences Bldg, 1 Kings College Circle, University of Toronto, ON, Canada, M5S 1A8
    J Appl Physiol 102:2240-50. 2007
    ..These results suggest that despite the upper airway narrowing in obese Zucker rats, these animals have a sufficiently stable airway such that pharyngeal muscle activity is normal across sleep-wake states...
  43. ncbi Cyclic nucleotides modulate genioglossus and hypoglossal responses to excitatory inputs in rats
    Cynthia R A Aoki
    Department of Medicine, University of Toronto, Toronto, ON, M5S 1A8, Canada
    Am J Respir Crit Care Med 173:555-65. 2006
    ..Whether modulation of intracellular pathways can increase pharyngeal muscle activity, however, has not been investigated but is relevant to pharmacologic treatments of obstructive sleep apnea...
  44. ncbi A serotonergic (5-HT2) receptor mechanism in the laterodorsal tegmental nucleus participates in regulating the pattern of rapid-eye-movement sleep occurrence in the rat
    Roberto Amici
    Department of Human and General Physiology, University of Bologna, Bologna, Italy
    Brain Res 996:9-18. 2004
    ..An opposite effect of ketanserin on REM sleep clusters, although not statistically significant, was observed...
  45. ncbi Arousal from sleep--perspectives relating to autonomic function
    Richard L Horner
    Sleep 26:644-5. 2003
  46. ncbi Contributions of passive mechanical loads and active neuromuscular compensation to upper airway collapsibility during sleep
    Richard L Horner
    J Appl Physiol 102:510-2. 2007