UCLA Neuroscience Program Ph.D. Admissions Neuroscience Faculty UCLA and Beyond  



Ronald Harper
Neural Mechanisms in Sleep State

Email Address:  rharper@ucla.edu

Work Address:
BRI
BRI


Phone Numbers:
310-206-1679 Laboratory
310-825-5303 Office


Selected Publications:

Macey PM, Kumar R, Woo MA, Valladares EM, Yan-Go FL, Harper RM. Brain structural changes in obstructive sleep apnea.. Sleep 2008; 31(7): 967-77.
Serber SL, Kumar R, Woo MA, Macey PM, Fonarow GC, Harper RM. Cognitive test performance and brain pathology.. Nurs Res. 2008; 57(2): 75-83.
Kumar R, Macey PM, Woo MA, Alger JR, Harper RM. Diffusion tensor imaging demonstrates brainstem and cerebellar abnormalities in congenital central hypoventilation syndrome.. Pediatr Res. 2008; 64(3): 275-80.
Cross RL, Kumar R, Macey PM, Doering LV, Alger JR, Yan-Go FL, Harper RM. Neural alterations and depressive symptoms in obstructive sleep apnea patients.. Sleep 2008; 31(8): 1103-9.
Kumar R, Birrer BV, Macey PM, Woo MA, Gupta RK, Yan-Go FL, Harper RM. Reduced mammillary body volume in patients with obstructive sleep apnea.. Neurosci Lett. 2008; 438(3): 330-4.
Woo MA, Macey PM, Keens PT, Kumar R, Fonarow GC, Hamilton MA, Harper RM. Aberrant central nervous system responses to the Valsalva maneuver in heart failure.. Congest Heart Fail 2007; 13(1): 29-35.
Martins N, Lopes I, Harper RM, Ross P, Ribeiro R. Differential resistance to copper and mine drainage in Daphnia longispina: relationship with allozyme genotypes.. Environ Toxicol Chem 2007; 26(9): 1904-9.
Macey PM, Woo MA, Harper RM. Hyperoxic brain effects are normalized by addition of CO2.. PLoS Med 2007; 4(5): e173.
Rector DM, Richard CA, Harper RM. Cerebellar fastigial nuclei activity during blood pressure challenges.. J Appl Physiol 2006; 101(2): 549-55.
Kumar R, Macey PM, Woo MA, Alger JR, Harper RM. Elevated mean diffusivity in widespread brain regions in congential central hypoventilation syndrome.. J Magn Reson Imaging 2006; 24(6): 1252-8.
Macey KE, Macey PM, Woo MA, Henderson LA, Frysinger RC, Harper RK, Alger JR, Yan-Go F, Harper RM. Inspiratory loading elicits aberrant fMRI signal changes in obstructive sleep apnea.. Respir Physiol Neurobiol 2006; 151(1): 44-60.
Krakow B, Melendrez D, Warner TD, Clark JO, Sisley BN, Dorin R, Harper RM, Leahigh LK, Lee SA, Sklar D, Hollifield M. Signs and symptoms of sleep-disordered breathing in trauma survivors: a matched comparison with classic sleep apnea patients.. J Nerv Ment Dis 2006; 194(6): 433-9.
Macey PM, Macey KE, Woo MA, Keens TG, Harper RM. Aberrant neural responses to cold pressor challenges in congenital central hypoventilation syndrome.. Pediatr Res 2005; 57(4): 500-9.
Woo MA, Macey PM, Mackey KE, Keens TG, Woo MS, Harper RK, Harper RM. FMRI responses to hyperoxia in congenital central hypoventilation syndrome.. Pediatr Res 2005; 57(4): 510-8.
Woo MA, Macey PM, Keens PT, Kumar R, Fonarow GC, Hamilton MA, Harper RM. Functional abnormalities in brain areas that mediate autonomic nervous system control in advanced heart failure.. J Card Fail 2005; 11(6): 437-46.
Harper RM, Macey PM, Woo MA, Macey KE, Keens TG, Gozal D, Alger JR. Hypercapnic exposure in congenital central hypoventilation syndrome reveals CNS respiratory control mechanisms.. J Neurophysiol 2005; 93(3): 1647-58.
Pae EK, Chien P, Harper RM. Intermittent hypoxia damages cerebellar cortex and deep nuclei.. Neurosci Lett 2005; 375(2): 123-8.
Kumar R, Macey PM, Woo MA, Alger JR, Keens TG, Harper RM. Neuroanatomic deficits in congenital central hypoventilation syndrome.. J Comp Neurol 2005; 487(4): 361-71.
Macey PM, Harper RM. OSA brain morphology differences: magnitude of loss approximates age-related effects.. Am J Respir Crit Care Med 2005; 172(8): 1056-7.
Macey PM, Macey KE, Kumar R, Harper RM. A method for removal of global effects from fMRI time series.. Neuroimage 2004; 22(1): 360-6.
Kristensen MP, Rector DM, Poe GR, Harper RM. Activity changes of the cat paraventricular hypothalamus during stressor exposure.. Neuroreport 2004; 15(1): 43-8.
Henderson LA, Macey PM, Richard CA, Runquist ML, Harper RM. Functional magnetic resonance imaging during hypotension in the developing animal.. J Appl Physiol 2004; 97(6): 2248-57.
Henderson LA, Richard CA, Macey PM, Runquist ML, Yu PL, Galons JP, Harper RM. Functional magnetic resonance signal changes in neural structures to baroreceptor reflex activation.. J Appl Physiol 2004; 96(2): 693-703.
Pae EK, Wu J, Nguyen D, Monti R, Harper RM. Geniohyoid muscle properties and myosin heavy chain composition are altered after short-term intermittent hypoxic exposure.. J Appl Physiol 2004; 98(3): 889-94.
Macey PM, Woo MA, Macey KE, Keens TG, Saeed MM, Alger JR, Harper RM. Hypoxia reveals posterior thalamic, cerebellar, midbrain, and limbic deficits in congenital central hypoventilation syndrome.. J Appl Physiol 2004; 98(3): 958-69.
Tatematsu K, Kumagai S, Muto H, Sato A, Watahiki MK, Harper RM, Liscum E, Yamamoto KT. MASSUGU2 encodes Aux/IAA19, an auxin-regulated protein that functions together with the transcriptional activator NPH4/ARF7 to regulate differential growth responses of hypocotyl adn formation of lateral roots in Arabidopsis thaliana.. Plant Cell 2004; 16(2): 379-93.
Macey PM, Valderama C, Kim AH, Woo MA, Gozal D, Keens TG, Harper RK, Harper RM. Temporal trends of cardiac and respiratory responses to ventilatory challenges in congenital central hypoventilation syndrome.. Pediatr Res 2004; 55(6): 953-9.
Macey KE, Macey PM, Woo MA, Harper RK, Alger JR, Keens TG, Harper RM. fMRI signal changes in response to forced expiratory loading in congenital central hypoventilation syndrome.. J Appl Physiol 2004; 97(5): 1897-907.
Macey PM, Macey KE, Henderson LA, Alger JR, Frysinger RC, Woo MA, Yan-Go F, Harper RM. Functional magnetic resonance imaging responses to expiratory loading in obstructive sleep apnea.. Respir Physiol Neurobiol 2003; 138(2-3): 275-90.
Macey PM, Alger JR, Kumar R, Macey KE, Woo MA, Harper RM. Global BOLD MRI changes to ventilatory challenges in congenital central hypoventilation syndrome.. Respir Physiol Neurobiol 2003; 139(1): 41-50.
Harper RM. Impaired arousals and sudden infant death syndrome: preexisting neural injury?. Am J Respir Crit Care Med 2003; 168(11): 1262-3.
Richard CA, Rector DM, Macey PM, Ali N, Harper RM Late-developing rostral ventral lateral medullary surface responses to cardiovascular challenges during sleep.. Brain Res 2003; 985: 65-77.
Richard CA, Rector DM, Macey PM, Ali N, Harper RM. Late-developing rostral ventrolateral medullary surface responses to cardiovascular challenges during sleep.. Brain Res 2003; 985(1): 65-77.
Henderson LA, Woo MA, Macey PM, Macey KE, Frysinger RC, Alger JR, Yan-GO F, Harper RM. Neural responses during Valsalva maneuvers in obstructive sleep apnea syndrome.. J Appl Physiol 2003; 94(3): 1063-74.
Woo MA, Macey PM, Fonarow GC, Hamilton MA, Harper RM. Regional brain gray matter loss in heart failure.. J Appl Physiol 2003; 95(2): 677-84.
Poe GR, Rector DM, Harper RM. State-dependent columnar organization of dorsal hippocampal activity in the freely-behaving cat.. Behav Brain Res 2003; 138(1): 107-12.
Harper RM, Macey PM, Henderson LA, Woo MA, Macey KE, Frysinger RC, Alger JR, Nguyen KP, Yan-Go FL. fMRI responses to cold pressor challenges in control and obstructive sleep apnea subjects.. J Appl Physiol 2003; 94(4): 1583-95.
Macey PM, Henderson LA, Macey KE, Alger JR, Frysinger RC, Woo MA, Harper RK, Yan-GO FL, Harper RM. Brain morphology associated with obstructive sleep apnea.. Am J Respir Crit Care Med 2002; 166(10): 1382-7.
Henderson LA, Macey PM, Macey KE, Frysinger RC, Woo MA, Harper RK, Alger JR, Yan-Go FL, Harper RM. Brain responses associated with the Valsalva maneuver revealed by functional magnetic resonance imaging.. J Neurophysiol 2002; 88(6): 3477-86.
Kim AH, Macey PM, Woo MA, Yu PL, Keens TG, Alger JR, Gozal D, Harper RK, Harper RM Cardiac responses to pressor challenges in Congenital Central Hypoventilation Syndrome.. Somnology 2002; 6(3): 109-115.
Henderson LA, Yu PL, Frysinger RC, Galons JP, Bandler R, Harper RM Neural responses to intravenous serotonin revealed by functional magnetic resonance imaging.. J Appl Physiol 2002; 92(1): 331-42.
Harper RM, Richard CA, Henderson LA, Macey PM, Macey KE. Structural mechanism underlying autonomic reactions in pediatric arousal.. Sleep Med 2002; 3(Suppl 2): S53-6.
Harper RM. The cerebellum and respiratory control.. Cerebellum 2002; 1(1): 1-2.
Henderson LA, Frysinger RC, Yu PL, Bandler R, Harper RM. A device for feline head positioning and stabilization during magnetic resonance imaging.. Magn Reson Imaging 2001; 19(7): 1031-6.
Harper RM. Autonomic control during sleep and risk for sudden death in infancy.. Arch Ital Biol 2001; 139(3): 185-94.
Rector DM, Rogers RF, Schwaber JS, Harper RM, George JS. Scattered-light imaging in vivo tracks fast and slow processes of neurophysiological activation.. Neuroimage 2001; 14(5): 977-94.
Harper RM. Visualization of neural activity associated with dyspnea.. Am J Respir Crit Care Med 2001; 163(4): 805-6.
Richard CA, Rector D, Macey P, Harper RM Changes in vental medullary light reflectance during hypercapnia in awake and sleeping cats.. Neurosci Lett 2000; 286: 175-178.
Macey PM, Richard CA, Rector DM, Harper RK, Harper RM. State influences on ventral medullary surface and physiological responses to sodium cyanide challenges.. J Appl Physiol 2000; 89(5): 1919-27.
Harper RM, Woo MA, Alger JR. Visualization of sleep influences on cerebellar and brainstem cardiac and respiratory control mechanisms.. Brain Res Bull 2000; 53(1): 125-31.
Harper, RM Richard, CA Rector, DM Physiological and ventral medullary surface activity during hypovolemia.. Neuroscience. . 1999; 94(2): 579-86.
Rector DM, Poe GR, Kristensen MP, Harper RM Light scattering changes follow evoked potentials from hippocampal Schaeffer's collateral stimulation.. J Neurosci ethods 1997; 78: 1707-1713.
Mayhew JEW, Askew S, Zheng Y, Porrill J, Westby GWM, Redgrave P, Rector DM, Harper RM Cerebral vasomotion:0.1 Hz oscilation in reflected light imaging of neural activity.. NeuroImage 1996; 4: 183-193.
Colder BW, Wilson CL, Frysinger RC, Harper RM, Engel J, Jr Inter-spike intervals during interictal periods in human temporal lobe epilepsy.. Brain Res 1996; 719: 96-103.
Gozal, D Dong, XW Rector, DM Harper, RK Harper, RM Optical imaging of the ventral medullary surface of developing kittens during ventilatory challenges.. Reproduction, fertility, and development. . 1996; 8(1): 87-95.
Ni, H Schechtman, VL Zhang, J Glotzbach, SF Harper, RM Respiratory responses to preoptic/anterior hypothalamic warming during sleep in kittens.. Reproduction, fertility, and development. . 1996; 8(1): 79-86.
Rector DM, Poe GR, Kristensen MP, Harper RM Imaging the dorsal hippocampus: Light reflectance relationships to electro-encephalographic patterns during sleep.. Brain Res 1995; 696: 151-160.
Gozal, D Dong, XW Rector, DM Harper, RM Maturation of kitten ventral medullary surface activity during pressor challenges.. Developmental neuroscience. . 1995; 17(4): 236-45.
Harper, R.M., Gozal, D., Aljadeff, G., Carroll, J.L., Dong, X.W., Rector, D.M. Optical imaging of pressor-induced neural activation of the cat ventral medullary surface.. Am J Physiol 1995; 268: R324-R333.
Aljadeff, G Gozal, D Carroll, JL Rector, DM Harper, RM Ventral medullary surface responses to hypoxic and hyperoxic transient ventilatory challenges in the cat.. Life sciences. . 1995; 57(4): 319-24.
Henderson LA, Macey KE, Macey PM, Woo MA, Yan-Go FL, Harper RM. Regional brain response patterns to Cheyne-Stokes breathing.. Respir Physiol Neurobiol 93; 150(1): 87.
Harper, RM Macey, PM Woo, MA Macey, KE Keens, TG Gozal, D Alger, JR Hypercapnic exposure in congenital central hypoventilation syndrome reveals CNS respiratory control mechanisms.. Journal of neurophysiology. . 2005; 93(3): 1647-58.
Macey, KE Macey, PM Woo, MA Harper, RK Alger, JR Keens, TG Harper, RM fMRI signal changes in response to forced expiratory loading in congenital central hypoventilation syndrome.. Journal of applied physiology (Bethesda, Md. : 1985) . 2004; 97(5): 1897-907.
Macey, PM Valderama, C Kim, AH Woo, MA Gozal, D Keens, TG Harper, RK Harper, RM Temporal trends of cardiac and respiratory responses to ventilatory challenges in congenital central hypoventilation syndrome.. Pediatric research. . 2004; 55(6): 953-9.
Macey, PM Macey, KE Kumar, R Harper, RM A method for removal of global effects from fMRI time series.. NeuroImage. . 2004; 22(1): 360-6.
Henderson, LA Richard, CA Macey, PM Runquist, ML Yu, PL Galons, JP Harper, RM Functional magnetic resonance signal changes in neural structures to baroreceptor reflex activation.. Journal of applied physiology (Bethesda, Md. : 1985) . 2004; 96(2): 693-703.
Macey, PM Alger, JR Kumar, R Macey, KE Woo, MA Harper, RM Global BOLD MRI changes to ventilatory challenges in congenital central hypoventilation syndrome.. Respiratory physiology & neurobiology. . 2003; 139(1): 41-50.
Macey, PM Macey, KE Henderson, LA Alger, JR Frysinger, RC Woo, MA Yan-Go, F Harper, RM Functional magnetic resonance imaging responses to expiratory loading in obstructive sleep apnea.. Respiratory physiology & neurobiology. . 2003; 138(2-3): 275-90.
Woo, MA Macey, PM Fonarow, GC Hamilton, MA Harper, RM Regional brain gray matter loss in heart failure.. Journal of applied physiology (Bethesda, Md. : 1985) . 2003; 95(2): 677-84.
Harper, RM Macey, PM Henderson, LA Woo, MA Macey, KE Frysinger, RC Alger, JR Nguyen, KP Yan-Go, FL fMRI responses to cold pressor challenges in control and obstructive sleep apnea subjects.. Journal of applied physiology (Bethesda, Md. : 1985) . 2003; 94(4): 1583-95.
Henderson, LA Woo, MA Macey, PM Macey, KE Frysinger, RC Alger, JR Yan-Go, F Harper, RM Neural responses during Valsalva maneuvers in obstructive sleep apnea syndrome.. Journal of applied physiology (Bethesda, Md. : 1985) . 2003; 94(3): 1063-74.
Poe, GR Rector, DM Harper, RM State-dependent columnar organization of dorsal hippocampal activity in the freely-behaving cat.. Behavioural brain research. . 2003; 138(1): 107-12.
Henderson, LA Macey, PM Macey, KE Frysinger, RC Woo, MA Harper, RK Alger, JR Yan-Go, FL Harper, RM Brain responses associated with the Valsalva maneuver revealed by functional magnetic resonance imaging.. Journal of neurophysiology. . 2002; 88(6): 3477-86.
Krakow, B Melendrez, D Warner, TD Dorin, R Harper, R Hollifield, M To breathe, perchance to sleep: sleep-disordered breathing and chronic insomnia among trauma survivors.. Sleep & breathing = Schlaf & Atmung. . 2002; 6(4): 189-202.
Henderson, LA Yu, PL Frysinger, RC Galons, JP Bandler, R Harper, RM Neural responses to intravenous serotonin revealed by functional magnetic resonance imaging.. Journal of applied physiology (Bethesda, Md. : 1985) . 2002; 92(1): 331-42.
Rector, DM Rogers, RF Schwaber, JS Harper, RM George, JS Scattered-light imaging in vivo tracks fast and slow processes of neurophysiological activation.. NeuroImage. . 2001; 14(5): 977-94.
Henderson, LA Frysinger, RC Yu, PL Bandler, R Harper, RM A device for feline head positioning and stabilization during magnetic resonance imaging.. Magnetic resonance imaging. . 2001; 19(7): 1031-6.
Macey, PM Richard, CA Rector, DM Harper, RK Harper, RM State influences on ventral medullary surface and physiological responses to sodium cyanide challenges.. Journal of applied physiology (Bethesda, Md. : 1985) . 2000; 89(5): 1919-27.
Rector, DM Richard, CA Staba, RJ Harper, RM Sleep states alter ventral medullary surface responses to blood pressure challenges.. American journal of physiology. Regulatory, integrative and comparative physiology. . 2000; 278(4): R1090-8.
Harper, RM Bandler, R Spriggs, D Alger, JR Lateralized and widespread brain activation during transient blood pressure elevation revealed by magnetic resonance imaging.. The Journal of comparative neurology. . 2000; 417(2): 195-204.
Richard, CA Rector, DM Harper, RK Harper, RM Optical imaging of the ventral medullary surface across sleep-wake states.. The American journal of physiology. . 1999; 277(4 Pt 2): R1239-45.
Harper, RM Gozal, D Bandler, R Spriggs, D Lee, J Alger, J Regional brain activation in humans during respiratory and blood pressure challenges.. Clinical and experimental pharmacology & physiology. . 1998; 25(6): 483-6.
Schechtman, VL Henslee, JA Harper, RM Developmental patterns of heart rate and variability in infants with persistent apnea of infancy.. Early human development. . 1998; 50(3): 251-62.
Rector, DM Poe, GR Redgrave, P Harper, RM A miniature CCD video camera for high-sensitivity light measurements in freely behaving animals.. Journal of neuroscience methods. . 1997; 78(1-2): 85-91.
Kristensen, MP Poe, GR Rector, DM Harper, RM Activity changes of the cat paraventricular hypothalamus during phasic respiratory events.. Neuroscience. . 1997; 80(3): 811-9.
Aljadeff, G Gozal, D Schechtman, VL Burrell, B Harper, RM Ward, SL Heart rate variability in children with obstructive sleep apnea.. Sleep. . 1997; 20(2): 151-7.
Henslee, JA Schechtman, VL Lee, MY Harper, RM Developmental patterns of heart rate and variability in prematurely-born infants with apnea of prematurity.. Early human development. . 1997; 47(1): 35-50.
Schechtman, VL Ni, H Glotzbach, SF Harper, RM Sleep state effects on nonpanting breathing during preoptic/anterior hypothalamic warming in cats and kittens.. Sleep. . 1997; 20(1): 1-10.
Schechtman, VL Lee, MY Wilson, AJ Harper, RM Dynamics of respiratory patterning in normal infants and infants who subsequently died of the sudden infant death syndrome.. Pediatric research. . 1996; 40(4): 571-7.
Carroll, JL Gozal, D Rector, DM Aljadeff, G Harper, RM Ventral medullary neuronal responses to peripheral chemoreceptor stimulation.. Neuroscience. . 1996; 73(4): 989-98.
Kristensen, MP Rector, DM Poe, GR Harper, RM State-dependent cellular activity patterns of the cat paraventricular hypothalamus measured by reflectance imaging.. Brain research. . 1996; 727(1-2): 107-17.
Colder, BW Wilson, CL Frysinger, RC Chao, LC Harper, RM Engel, J Neuronal synchrony in relation to burst discharge in epileptic human temporal lobes.. Journal of neurophysiology. . 1996; 75(6): 2496-508.
Poe, GR Kristensen, MP Rector, DM Harper, RM Hippocampal activity during transient respiratory events in the freely behaving cat.. Neuroscience. . 1996; 72(1): 39-48.
Poe, GR Nitz, DA Rector, DM Kristensen, MP Harper, RM Concurrent reflectance imaging and microdialysis in the freely behaving cat.. Journal of neuroscience methods. . 1996; 65(2): 143-9.
Colder, BW Frysinger, RC Wilson, CL Harper, RM Engel, J Decreased neuronal burst discharge near site of seizure onset in epileptic human temporal lobes.. Epilepsia. . 1996; 37(2): 113-21.
Gozal, D Omidvar, O Kirlew, KA Hathout, GM Lufkin, RB Harper, RM Functional magnetic resonance imaging reveals brain regions mediating the response to resistive expiratory loads in humans.. The Journal of clinical investigation. . 1996; 97(1): 47-53.
Harper, RM Gozal, D Forster, HV Ohtake, PJ Pan, LG Lowry, TF Rector, DM Imaging of VMS activity during blood pressure challenges in awake and anesthetized goats.. The American journal of physiology. . 1996; 270(1 Pt 2): R182-91.
Forster, HV Gozal, D Harper, RM Lowry, TF Ohtake, PJ Pan, LG Rector, DM Ventral medullary surface activity during hypoxia in awake and anesthetized goats.. Respiration physiology. . 1996; 103(1): 45-56.
Hathout, GM Gambhir, SS Gopi, RK Kirlew, KA Choi, Y So, G Gozal, D Harper, R Lufkin, RB Hawkins, R A quantitative physiologic model of blood oxygenation for functional magnetic resonance imaging.. Investigative radiology. . 1995; 30(11): 669-82.
Gozal, D Arens, R Omlin, KJ Ben-Ari, JH Aljadeff, G Harper, RM Keens, TG Ventilatory response to consecutive short hypercapnic challenges in children with obstructive sleep apnea.. Journal of applied physiology (Bethesda, Md. : 1985) . 1995; 79(5): 1608-14.
Gozal, D Omidvar, O Kirlew, KA Hathout, GM Hamilton, R Lufkin, RB Harper, RM Identification of human brain regions underlying responses to resistive inspiratory loading with functional magnetic resonance imaging.. Proceedings of the National Academy of Sciences of the United States of America. . 1995; 92(14): 6607-11.
Gozal, D Omidvar, O Kirlew, KA Hathout, GM Hamilton, R Lufkin, RB Harper, RM Identification of human brain regions underlying responses to resistive inspiratory loading with functional magnetic resonance imaging.. Proceedings of the National Academy of Sciences of the United States of America. . 1995; 92(14): 6607-11.
Gozal, D Ohtake, PJ Rector, DM Lowry, TF Pan, LG Forster, HV Harper, RM Rostral ventral medullary surface activity during hypercapnic challenges in awake and anesthetized goats.. Neuroscience letters. . 1995; 192(2): 89-92.
Terreberry, RR Oguri, M Harper, RM State-dependent respiratory and cardiac relationships with neuronal discharge in the bed nucleus of the stria terminalis.. Sleep. . 1995; 18(3): 139-44.
Rector, D Harper, R Imaging of hippocampal neural activity in freely behaving animals.. Behavioural brain research. . 1991; 42(2): 143-9.
Research Interest:

The laboratory examines neural mechanisms underlying sleep state: control of breathing, somatomotor activity, and cardiovascular action in developing and adult small animal preparations. Neural mechanisms are examined through neurophysiologic techniques which include assessment of intrinsic optical changes in neural tissue, functional magnetic resonance imaging, and chronic single neuron recording; the optical imaging and cell recording studies are often combined with microdialysis techniques to determine neurochemical mechanisms underlying cell action. We found that a substantial portion of sleep effects on normal and disordered breathing result from rostral brain influences on pontine and medullary structures, that activity over wide areas of these structures can be visualized during ventilatory and pressor challenges in freely behaving animals, and that immature development of mechanisms controlling descending rostral brain influences on breathing can place the organism at risk.