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Respiratory control by ventral surface chemoreceptor neurons in rats

Nature Neuroscience volume 7, pages 1360–1369 (2004)Cite this article

Abstract

A long-standing theory posits that central chemoreception, the CNS mechanism for CO2 detection and regulation of breathing, involves neurons located at the ventral surface of the medulla oblongata (VMS). Using in vivo and in vitro electrophysiological recordings, we identify VMS neurons within the rat retrotrapezoid nucleus (RTN) that have characteristics befitting these elusive chemoreceptors. These glutamatergic neurons are vigorously activated by CO2 in vivo, whereas serotonergic neurons are not. Their CO2 sensitivity is unaffected by pharmacological blockade of the respiratory pattern generator and persists without carotid body input. RTN CO2-sensitive neurons have extensive dendrites along the VMS and they innervate key pontomedullary respiratory centers. In brainstem slices, a subset of RTN neurons with markedly similar morphology is robustly activated by acidification and CO2. Their pH sensitivity is intrinsic and involves a background K+ current. In short, the CO2-sensitive neurons of the RTN are good candidates for the long sought-after VMS chemoreceptors.

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Figure 1: Properties of RTN CO2-activated neurons in vivo.
Figure 2: Response of RTN neurons to CO2 in vivo after pharmacological blockade of the CPG.
Figure 3: Anatomical definition of RTN and phenotype of CO2-activated neurons.
Figure 4: CO2 does not activate serotonergic neurons in vivo.
Figure 5: pH sensitivity of RTN neurons in vitro.
Figure 6: pH sensitivity of RTN neurons involves a background K+ channel.

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References

  1. Feldman, J.L., Mitchell, G.S. & Nattie, E.E. Breathing: rhythmicity, plasticity, chemosensitivity. Annu. Rev. Neurosci. 26, 239–266 (2003).

    Article  CAS  Google Scholar 

  2. Richerson, G.B. Serotonergic neurons as carbon dioxide sensors that maintain pH homeostasis. Nat. Rev. Neurosci. 5, 449–461 (2004).

    Article  CAS  Google Scholar 

  3. Ballantyne, D. & Scheid, P. Central chemosensitivity of respiration: a brief overview. Respir. Physiol. 129, 5–12 (2001).

    Article  CAS  Google Scholar 

  4. Scheid, P., Putnam, R.W., Dean, J.B. & Ballantyne, D. (eds.) Special issue: central chemosensitivity. Respir. Physiol. Neurobiol. 129, 1–278 (2001).

    Article  Google Scholar 

  5. Kawai, A., Ballantyne, D., Muckenhoff, K. & Scheid, P. Chemosensitive medullary neurones in the brainstem–spinal cord preparation of the neonatal rat. J. Physiol. (Lond.) 492, 277–292 (1996).

    Article  CAS  Google Scholar 

  6. Nattie, E.E. Central chemosensitivity, sleep, and wakefulness. Respir. Physiol. 129, 257–268 (2001).

    Article  CAS  Google Scholar 

  7. Mitchell, R.A., Loeschcke, H.H., Massion, W.H. & Severinghaus, J.W. Respiratory responses mediated through superficial chemosensitive areas on the medulla. J. Appl. Physiol. 18, 523–533 (1963).

    Article  CAS  Google Scholar 

  8. Loeschcke, H.H. Central chemosensitivity and the reaction theory. J. Physiol. (Lond.) 332, 1–24 (1982).

    Article  CAS  Google Scholar 

  9. Smith, J.C., Morrison, D.E., Ellenberger, H.H., Otto, M.R. & Feldman, J.L. Brainstem projections to the major respiratory neuron populations in the medulla of the cat. J. Comp. Neurol. 281, 69–96 (1989).

    Article  CAS  Google Scholar 

  10. Cream, C., Li, A. & Nattie, E. The retrotrapezoid nucleus (RTN): local cytoarchitecture and afferent connections. Respir. Physiol. Neurobiol. 130, 121–137 (2002).

    Article  Google Scholar 

  11. Ellenberger, H.H. & Feldman, J.L. Brainstem connections of the rostral ventral respiratory group of the rat. Brain Res. 513, 35–42 (1990).

    Article  CAS  Google Scholar 

  12. Connelly, C.A., Ellenberger, H.H. & Feldman, J.L. Are there serotonergic projections from raphe and retrotrapezoid nuclei to the ventral respiratory group in the rat? Neurosci. Lett. 105, 34–40 (1989).

    Article  CAS  Google Scholar 

  13. Weston, M.C., Stornetta, R.L. & Guyenet, P.G. Glutamatergic neuronal projections from the marginal layer of the rostral ventral medulla to the respiratory centers in rats. J. Comp. Neurol. 473, 73–85 (2004).

    Article  Google Scholar 

  14. Okada, Y., Chen, Z., Jiang, W., Kuwana, S. & Eldridge, F.L. Anatomical arrangement of hypercapnia-activated cells in the superficial ventral medulla of rats. J. Appl. Physiol. 93, 427–439 (2002).

    Article  Google Scholar 

  15. Sato, M., Severinghaus, J.W. & Basbaum, A.I. Medullary CO2 chemoreceptor neuron identification by c-fos immunocytochemistry. J. Appl. Physiol. 73, 96–100 (1992).

    Article  CAS  Google Scholar 

  16. Onimaru, H. & Homma, I. A novel functional neuron group for respiratory rhythm generation in the ventral medulla. J. Neurosci. 23, 1478–1486 (2003).

    Article  CAS  Google Scholar 

  17. Fukuda, Y., Tojima, H., Tanaka, K. & Chiba, T. Respiratory suppression by focal cooling of ventral medullary surface in anesthetized rats—functional and neuroanatomical correlate. Neurosci. Lett. 153, 177–180 (1993).

    Article  CAS  Google Scholar 

  18. Orem, J. & Dick, T. Consistency and signal strength of respiratory neuronal activity. J. Neurophysiol. 50, 1098–1107 (1983).

    Article  CAS  Google Scholar 

  19. Stornetta, R.L., Sevigny, C.P. & Guyenet, P.G. Inspiratory augmenting bulbospinal neurons express both glutamatergic and enkephalinergic phenotypes. J. Comp. Neurol. 455, 113–124 (2003).

    Article  CAS  Google Scholar 

  20. Brown, D.L. & Guyenet, P.G. Electrophysiological study of cardiovascular neurons in the rostral ventrolateral medulla in rats. Circ. Res. 56, 359–369 (1985).

    Article  CAS  Google Scholar 

  21. Sun, M.K. Pharmacology of reticulospinal vasomotor neurons in cardiovascular regulation. Pharmacol. Rev. 48, 465–494 (1996).

    CAS  PubMed  Google Scholar 

  22. Bianchi, A.L., Denavit-Saubie, M. & Champagnat, J. Central control of breathing in mammals: neuronal circuitry, membrane properties, and neurotransmitters. Physiol. Rev. 75, 1–45 (1995).

    Article  CAS  Google Scholar 

  23. Sun, M.K., Hackett, J.T. & Guyenet, P.G. Sympathoexcitatory neurons of rostral ventrolateral medulla exhibit pacemaker properties in the presence of a glutamate- receptor antagonist. Brain Res. 438, 23–40 (1988).

    Article  CAS  Google Scholar 

  24. Gray, P.A., Rekling, J.C., Bocchiaro, C.M. & Feldman, J.L. Modulation of respiratory frequency by peptidergic input to rhythmogenic neurons in the PreBotzinger complex. Science 286, 1566–1568 (1999).

    Article  CAS  Google Scholar 

  25. Manzke, T. et al. 5-HT4(a) receptors avert opioid-induced breathing depression without loss of analgesia. Science 301, 226–229 (2003).

    Article  CAS  Google Scholar 

  26. Schreihofer, A.M. & Guyenet, P.G. Identification of C1 presympathetic neurons in rat rostral ventrolateral medulla by juxtacellular labeling in vivo. J. Comp. Neurol. 387, 524–536 (1997).

    Article  CAS  Google Scholar 

  27. St-John, W.M. Neurogenesis of patterns of automatic ventilatory activity. Prog. Neurobiol. 56, 97–117 (1998).

    Article  CAS  Google Scholar 

  28. Paxinos, G. & Watson, C. The Rat Brain in Stereotaxic Coordinates 4th edn. (Academic, San Diego, 1998).

    Google Scholar 

  29. Fremeau, R.T., Voglmaier, S., Seal, R.P. & Edwards, R.H. VGLUTs define subsets of excitatory neurons and suggest novel roles for glutamate. Trends Neurosci. 27, 98–103 (2004).

    Article  CAS  Google Scholar 

  30. Mason, P. Contributions of the medullary raphe and ventromedial reticular region to pain modulation and other homeostatic functions. Annu. Rev. Neurosci. 24, 737–777 (2001).

    Article  CAS  Google Scholar 

  31. Eldridge, F.L., Kiley, J.P. & Millhorn, D.E. Respiratory responses to medullary hydrogen ion changes in cats: different effects of respiratory and metabolic acidoses. J. Physiol. (Lond.) 358, 285–297 (1985).

    Article  CAS  Google Scholar 

  32. Li, A. & Nattie, E. CO2 dialysis in one chemoreceptor site, the RTN: stimulus intensity and sensitivity in the awake rat. Respir. Physiol. Neurobiol. 133, 11–22 (2002).

    Article  Google Scholar 

  33. Bayliss, D.A., Talley, E.M., Sirois, J.E. & Lei, Q.B. TASK-1 is a highly modulated pH-sensitive 'leak' K+ channel expressed in brainstem respiratory neurons. Respir. Physiol. 129, 159–174 (2001).

    Article  CAS  Google Scholar 

  34. Washburn, C.P., Sirois, J.E., Talley, E.M., Guyenet, P.G. & Bayliss, D.A. Serotonergic raphe neurons express TASK channel transcripts and a TASK-like pH-and halothane-sensitive K+ conductance. J. Neurosci. 22, 1256–1265 (2002).

    Article  CAS  Google Scholar 

  35. Putnam, R.W., Filosa, J.A. & Ritucci, N.A. Cellular mechanisms involved in CO2 and acid signaling in chemosensitive neurons. Am. J. Physiol. — Cell Physiol. 287, C1493–C1526 (2004).

    Article  CAS  Google Scholar 

  36. Feldman, J.L. & McCrimmon, D.R. Neural control of breathing. in Fundamental Neuroscience (eds. Zigmond, M.J. et al.) 1063–1090 (Academic Press, San Diego, 1999).

    Google Scholar 

  37. Richerson, G.B. Response to CO2 of neurons in the rostral ventral medulla in vitro. J. Neurophysiol. 73, 933–944 (1995).

    Article  CAS  Google Scholar 

  38. Veasey, S.C., Fornal, C.A., Metzler, C.W. & Jacobs, B.L. Response of serotonergic caudal raphe neurons in relation to specific motor activities in freely moving cats. J. Neurosci. 15, 5346–5359 (1995).

    Article  CAS  Google Scholar 

  39. Nattie, E.E., Li, A., Richerson, G.B. & Lappi, D.A. Medullary serotonergic neurons and adjacent neurons that express neurokinin-1 receptors are both involved in chemoreception in vivo. J. Physiol. (Lond.) 556(Pt 1), 235–253 (2004).

    Article  Google Scholar 

  40. Shigetomi, E. & Kato, F. Action potential-independent release of glutamate by Ca2+ entry through presynaptic P2X receptors elicits postsynaptic firing in the brainstem autonomic network. J. Neurosci. 24, 3125–3135 (2004).

    Article  CAS  Google Scholar 

  41. Spyer, K.M., Dale, N. & Gourine, A.V. ATP is a key mediator of central and peripheral chemosensory transduction. Exp. Physiol. 89, 53–59 (2004).

    Article  CAS  Google Scholar 

  42. Xu, H., Cui, N., Yang, Z., Qu, Z. & Jiang, C. Modulation of kir4.1 and kir5.1 by hypercapnia and intracellular acidosis. J. Physiol. (Lond.) 524, 725–735 (2000).

    Article  CAS  Google Scholar 

  43. Pineda, J. & Aghajanian, G.K. Carbon dioxide regulates the tonic activity of locus coeruleus neurons by modulating a proton- and polyamine-sensitive inward rectifier potassium current. Neuroscience 77, 723–743 (1997).

    Article  CAS  Google Scholar 

  44. Wellner-Kienitz, M.C., Shams, H. & Scheid, P. Contribution of Ca2+-activated K+ channels to central chemosensitivity in cultivated neurons of fetal rat medulla. J. Neurophysiol. 79, 2885–2894 (1998).

    Article  CAS  Google Scholar 

  45. Sirois, J.E., Lei, Q.B., Talley, E.M., Lynch, C., III & Bayliss, D.A. The TASK-1 two-pore domain K+ channel is a molecular substrate for neuronal effects of inhalation anesthetics. J. Neurosci. 20, 6347–6354 (2000).

    Article  CAS  Google Scholar 

  46. Lipski, J. Antidromic activation of neurones as an analytical tool in the study of the central nervous system. J. Neurosci. Methods 4, 1–32 (1981).

    Article  CAS  Google Scholar 

  47. Haselton, J.R. & Guyenet, P.G. Central respiratory modulation of medullary sympathoexcitatory neurons in rat. Am. J. Physiol. 256, R739–R750 (1989).

    CAS  PubMed  Google Scholar 

  48. Leong, S.K. & Ling, E.A. Labelling neurons with fluorescent dyes administered via intravenous, subcutaneous or intraperitoneal route. J. Neurosci. Methods 32, 15–23 (1990).

    Article  CAS  Google Scholar 

  49. Bohn, M.C., Dreyfus, C.F., Friedman, W.J. & Markey, K.A. Glucocorticoid effects on phenylethanolamine N-methyltransferase (PNMT) in explants of embryonic rat medulla oblongata. Brain Res. 465, 257–266 (1987).

    Article  CAS  Google Scholar 

  50. Stornetta, R.L. et al. A group of glutamatergic interneurons expressing high levels of both neurokinin-1 receptors and somatostatin identifies the region of the pre-Botzinger complex. J. Comp. Neurol. 455, 499–512 (2003).

    Article  CAS  Google Scholar 

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Acknowledgements

This work was supported by grants NS33583 (D.A.B.), HL074011 (P.G.G.) and 5T32DK007646 (D.K.M.) from the US National Institutes of Health.

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  1. Department of Pharmacology, University of Virginia, Charlottesville, 22908, Virginia, USA

    Daniel K Mulkey, Ruth L Stornetta, Matthew C Weston, Johnny R Simmons, Anson Parker, Douglas A Bayliss & Patrice G Guyenet

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Correspondence to Patrice G Guyenet.

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Supplementary Fig. 1

Role of RTN in central chemoreception. (PDF 184 kb)

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Mulkey, D., Stornetta, R., Weston, M. et al. Respiratory control by ventral surface chemoreceptor neurons in rats. Nat Neurosci 7, 1360–1369 (2004). https://doi.org/10.1038/nn1357

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