Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Vesicular release of glutamate from unmyelinated axons in white matter

Nature Neuroscience volume 10, pages 321–330 (2007)Cite this article

Abstract

Directed fusion of transmitter-laden vesicles enables rapid intercellular signaling in the central nervous system and occurs at synapses within gray matter. Here we show that action potentials also induce the release of glutamate from axons in the corpus callosum, a white matter region responsible for interhemispheric communication. Callosal axons release glutamate by vesicular fusion, which induces quantal AMPA receptor–mediated currents in NG2+ glial progenitors at anatomically distinct axo–glial synaptic junctions. Glutamate release from axons was facilitated by repetitive stimulation and could be inhibited through activation of metabotropic autoreceptors. Although NG2+ cells form associations with nodes of Ranvier in white matter, measurements of conduction velocity indicated that unmyelinated fibers are responsible for glutamatergic signaling with NG2+ glia. This activity-dependent secretion of glutamate was prevalent in the developing and mature mouse corpus callosum, indicating that axons within white matter both conduct action potentials and engage in rapid neuron-glia communication.

This is a preview of subscription content, access via your institution

Relevant articles

Open Access articles citing this article.

Access options

Rent or buy this article

Get just this article for as long as you need it

$39.95

Learn more

Prices may be subject to local taxes which are calculated during checkout

Figure 1: NG2+ cells express DsRed in NG2-DsRed BAC mice.
Figure 2: Spontaneous release of glutamate within the corpus callosum activates AMPA receptors in NG2+ glial cells.
Figure 3: Stimulation of axons within the corpus callosum evokes the release of glutamate.
Figure 4: AMPAR currents in callosal NG2+ cells arise from vesicular release of glutamate.
Figure 5: AMPAR currents in NG2+ cells are not produced by reversed cycling of glutamate transporters or by vesicular release from astrocytes.
Figure 6: Axons form defined synaptic junctions with NG2+ cells within the corpus callosum.
Figure 7: Glutamate is released from unmyelinated axons in the corpus callosum.
Figure 8: NG2+ cells in the adult corpus callosum express Ca2+-permeable AMPARs.

References

  1. Barbour, B. An evaluation of synapse independence. J. Neurosci. 21, 7969–7984 (2001).

    Article  CAS  Google Scholar 

  2. Clancy, B., Silva-Filho, M. & Friedlander, M.J. Structure and projections of white matter neurons in the postnatal rat visual cortex. J. Comp. Neurol. 434, 233–252 (2001).

    Article  CAS  Google Scholar 

  3. Kriegler, S. & Chiu, S.Y. Calcium signaling of glial cells along mammalian axons. J. Neurosci. 13, 4229–4245 (1993).

    Article  CAS  Google Scholar 

  4. Fulton, B.P., Burne, J.F. & Raff, M.C. Visualization of O-2A progenitor cells in developing and adult rat optic nerve by quisqualate-stimulated cobalt uptake. J. Neurosci. 12, 4816–4833 (1992).

    Article  CAS  Google Scholar 

  5. Karadottir, R., Cavelier, P., Bergersen, L.H. & Attwell, D. NMDA receptors are expressed in oligodendrocytes and activated in ischaemia. Nature 438, 1162–1166 (2005).

    Article  CAS  Google Scholar 

  6. Hassel, B., Boldingh, K.A., Narvesen, C., Iversen, E.G. & Skrede, K.K. Glutamate transport, glutamine synthetase and phosphate-activated glutaminase in rat CNS white matter. A quantitative study. J. Neurochem. 87, 230–237 (2003).

    Article  CAS  Google Scholar 

  7. Follett, P.L., Rosenberg, P.A., Volpe, J.J. & Jensen, F.E. NBQX attenuates excitotoxic injury in developing white matter. J. Neurosci. 20, 9235–9241 (2000).

    Article  CAS  Google Scholar 

  8. Butt, A.M. et al. Cells expressing the NG2 antigen contact nodes of Ranvier in adult CNS white matter. Glia 26, 84–91 (1999).

    Article  CAS  Google Scholar 

  9. Bergles, D.E., Roberts, J.D., Somogyi, P. & Jahr, C.E. Glutamatergic synapses on oligodendrocyte precursor cells in the hippocampus. Nature 405, 187–191 (2000).

    Article  CAS  Google Scholar 

  10. Lin, S.C. et al. Climbing fiber innervation of NG2-expressing glia in the mammalian cerebellum. Neuron 46, 773–785 (2005).

    Article  CAS  Google Scholar 

  11. Yang, X.W., Model, P. & Heintz, N. Homologous recombination based modification in Escherichia coli and germline transmission in transgenic mice of a bacterial artificial chromosome. Nat. Biotechnol. 15, 859–865 (1997).

    Article  CAS  Google Scholar 

  12. Lin, S.C. & Bergles, D.E. Physiological characteristics of NG2-expressing glial cells. J. Neurocytol. 31, 537–549 (2002).

    Article  CAS  Google Scholar 

  13. Jacobson, S. & Trojanowski, J.Q. The cells of origin of the corpus callosum in rat, cat and rhesus monkey. Brain Res. 74, 149–155 (1974).

    Article  CAS  Google Scholar 

  14. Aram, J.A. & Lodge, D. Validation of a neocortical slice preparation for the study of epileptiform activity. J. Neurosci. Methods 23, 211–224 (1988).

    Article  CAS  Google Scholar 

  15. Capogna, M., Gahwiler, B.H. & Thompson, S.M. Calcium-independent actions of alpha-latrotoxin on spontaneous and evoked synaptic transmission in the hippocampus. J. Neurophysiol. 76, 3149–3158 (1996).

    Article  CAS  Google Scholar 

  16. Malgaroli, A., DeCamilli, P. & Meldolesi, J. Distribution of alpha latrotoxin receptor in the rat brain by quantitative autoradiography: comparison with the nerve terminal protein, synapsin I. Neuroscience 32, 393–404 (1989).

    Article  CAS  Google Scholar 

  17. Hanse, E. & Gustafsson, B. Quantal variability at glutamatergic synapses in area CA1 of the rat neonatal hippocampus. J. Physiol. (Lond.) 531, 467–480 (2001).

    Article  CAS  Google Scholar 

  18. Bruns, D., Riedel, D., Klingauf, J. & Jahn, R. Quantal release of serotonin. Neuron 28, 205–220 (2000).

    Article  CAS  Google Scholar 

  19. Volterra, A. & Meldolesi, J. Astrocytes, from brain glue to communication elements: the revolution continues. Nat. Rev. Neurosci. 6, 626–640 (2005).

    Article  CAS  Google Scholar 

  20. Zhou, Q., Petersen, C.C. & Nicoll, R.A. Effects of reduced vesicular filling on synaptic transmission in rat hippocampal neurones. J. Physiol. (Lond.) 525, 195–206 (2000).

    Article  CAS  Google Scholar 

  21. Wadiche, J.I., Arriza, J.L., Amara, S.G. & Kavanaugh, M.P. Kinetics of a human glutamate transporter. Neuron 14, 1019–1027 (1995).

    Article  CAS  Google Scholar 

  22. Hestrin, S., Sah, P. & Nicoll, R.A. Mechanisms generating the time course of dual component excitatory synaptic currents recorded in hippocampal slices. Neuron 5, 247–253 (1990).

    Article  CAS  Google Scholar 

  23. Fellin, T. et al. Neuronal synchrony mediated by astrocytic glutamate through activation of extrasynaptic NMDA receptors. Neuron 43, 729–743 (2004).

    Article  CAS  Google Scholar 

  24. Young, S.H. & Poo, M.M. Spontaneous release of transmitter from growth cones of embryonic neurones. Nature 305, 634–637 (1983).

    Article  CAS  Google Scholar 

  25. Shen, K. & Bargmann, C.I. The immunoglobulin superfamily protein SYG-1 determines the location of specific synapses in C. elegans. Cell 112, 619–630 (2003).

    Article  CAS  Google Scholar 

  26. Huang, J.K. et al. Glial membranes at the node of Ranvier prevent neurite outgrowth. Science 310, 1813–1817 (2005).

    Article  CAS  Google Scholar 

  27. Olivares, R., Montiel, J. & Aboitiz, F. Species differences and similarities in the fine structure of the mammalian corpus callosum. Brain Behav. Evol. 57, 98–105 (2001).

    Article  CAS  Google Scholar 

  28. Westrum, L.E. & Blackstad, T.W. An electron microscopic study of the stratum radiatum of the rat hippocampus (regio superior, CA 1) with particular emphasis on synaptology. J. Comp. Neurol. 119, 281–309 (1962).

    Article  CAS  Google Scholar 

  29. Preston, R.J., Waxman, S.G. & Kocsis, J.D. Effects of 4-aminopyridine on rapidly and slowly conducting axons of rat corpus callosum. Exp. Neurol. 79, 808–820 (1983).

    Article  CAS  Google Scholar 

  30. Lamantia, A.S. & Rakic, P. Cytological and quantitative characteristics of four cerebral commissures in the rhesus monkey. J. Comp. Neurol. 291, 520–537 (1990).

    Article  CAS  Google Scholar 

  31. Stallcup, W.B. The NG2 proteoglycan: past insights and future prospects. J. Neurocytol. 31, 423–435 (2002).

    Article  CAS  Google Scholar 

  32. Ughrin, Y.M., Chen, Z.J. & Levine, J.M. Multiple regions of the NG2 proteoglycan inhibit neurite growth and induce growth cone collapse. J. Neurosci. 23, 175–186 (2003).

    Article  CAS  Google Scholar 

  33. Yang, Z. et al. NG2 glial cells provide a favorable substrate for growing axons. J. Neurosci. 26, 3829–3839 (2006).

    Article  CAS  Google Scholar 

  34. Morgenstern, D.A. et al. Expression and glycanation of the NG2 proteoglycan in developing, adult, and damaged peripheral nerve. Mol. Cell. Neurosci. 24, 787–802 (2003).

    Article  CAS  Google Scholar 

  35. Stegmuller, J., Werner, H., Nave, K.A. & Trotter, J. The proteoglycan NG2 is complexed with α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors by the PDZ glutamate receptor interaction protein (GRIP) in glial progenitor cells. Implications for glial-neuronal signaling. J. Biol. Chem. 278, 3590–3598 (2003).

    Article  Google Scholar 

  36. Iino, M. et al. Glia-synapse interaction through Ca2+-permeable AMPA receptors in Bergmann glia. Science 292, 926–929 (2001).

    Article  CAS  Google Scholar 

  37. Yuan, X., Eisen, A.M., McBain, C.J. & Gallo, V. A role for glutamate and its receptors in the regulation of oligodendrocyte development in cerebellar tissue slices. Development 125, 2901–2914 (1998).

    CAS  PubMed  Google Scholar 

  38. Barres, B.A. & Raff, M.C. Proliferation of oligodendrocyte precursor cells depends on electrical activity in axons. Nature 361, 258–260 (1993).

    Article  CAS  Google Scholar 

  39. Bengtsson, S.L. et al. Extensive piano practicing has regionally specific effects on white matter development. Nat. Neurosci. 8, 1148–1150 (2005).

    Article  CAS  Google Scholar 

  40. Stevens, B., Porta, S., Haak, L.L., Gallo, V. & Fields, R.D. Adenosine: a neuron-glial transmitter promoting myelination in the CNS in response to action potentials. Neuron 36, 855–868 (2002).

    Article  CAS  Google Scholar 

  41. Dawson, M.R., Polito, A., Levine, J.M. & Reynolds, R. NG2-expressing glial progenitor cells: an abundant and widespread population of cycling cells in the adult rat CNS. Mol. Cell. Neurosci. 24, 476–488 (2003).

    Article  CAS  Google Scholar 

  42. Chittajallu, R., Aguirre, A. & Gallo, V. NG2-positive cells in the mouse white and grey matter display distinct physiological properties. J. Physiol. (Lond.) 561, 109–122 (2004).

    Article  CAS  Google Scholar 

  43. Gensert, J.M. & Goldman, J.E. Heterogeneity of cycling glial progenitors in the adult mammalian cortex and white matter. J. Neurobiol. 48, 75–86 (2001).

    Article  CAS  Google Scholar 

  44. McDonald, J.W., Althomsons, S.P., Hyrc, K.L., Choi, D.W. & Goldberg, M.P. Oligodendrocytes from forebrain are highly vulnerable to AMPA/kainate receptor-mediated excitotoxicity. Nat. Med. 4, 291–297 (1998).

    Article  CAS  Google Scholar 

  45. Rossi, D.J., Oshima, T. & Attwell, D. Glutamate release in severe brain ischaemia is mainly by reversed uptake. Nature 403, 316–321 (2000).

    Article  CAS  Google Scholar 

  46. Micu, I. et al. NMDA receptors mediate calcium accumulation in myelin during chemical ischaemia. Nature 439, 988–992 (2006).

    Article  CAS  Google Scholar 

  47. Jahr, C.E. High probability opening of NMDA receptor channels by L-glutamate. Science 255, 470–472 (1992).

    Article  CAS  Google Scholar 

  48. Tillet, E., Ruggiero, F., Nishiyama, A. & Stallcup, W.B. The membrane-spanning proteoglycan NG2 binds to collagens V and VI through the central nonglobular domain of its core protein. J. Biol. Chem. 272, 10769–10776 (1997).

    Article  CAS  Google Scholar 

  49. Bhat, M.A. et al. Axon-glia interactions and the domain organization of myelinated axons requires neurexin IV/Caspr/Paranodin. Neuron 30, 369–383 (2001).

    Article  CAS  Google Scholar 

  50. Fukaya, M. & Watanabe, M. Improved immunohistochemical detection of postsynaptically located PSD-95/SAP90 protein family by protease section pretreatment: a study in the adult mouse brain. J. Comp. Neurol. 426, 572–586 (2000).

    Article  CAS  Google Scholar 

Download references

Acknowledgements

We thank N. Heintz (Columbia University, New York) for providing BAC cloning reagents, B. Glick (University of Chicago) for the DsRed-T1 cDNA, W.B. Stallcup (Burnham Institute, San Diego) for antibodies to NG2 and PDGFαR, M.H. Bhat (University of North Carolina, Chapel Hill) for antibodies to Caspr, R. Edwards (University of California, San Francisco) for VGLUT1+/+ and VGLUT1−/− tissue, N. Nishiyama for assistance with PCR and mouse breeding, the IVAX Drug Research Institute for GYKI 53655, G. Ellis-Davies for MNI-D-aspartate, M. Watanabe for support and comments on the manuscript, J. Egen for assistance with confocal imaging and image analysis, and P. Somogyi for comments on the manuscript. This work was supported by the US National Institutes of Health grants NS051509 (D.E.B.), PAR-02-059 (D.E.B.) and NS049267 (A.N.), as well as by the March of Dimes (D.E.B.), NARSAD (D.E.B.), the National Multiple Sclerosis Society (A.N.) and the Medical Scientist Training Program (J.L.Z.).

Author information

Authors and Affiliations

  1. Department of Neuroscience, Johns Hopkins University School of Medicine, 725 N. Wolfe St., WBSB 813, Baltimore, 21205, Maryland, USA

    Jennifer L Ziskin & Dwight E Bergles

  2. Department of Neurobiology and Physiology, University of Connecticut, 75 North Eagleville Road, Unit 3156, Storrs, 06269-3156, Connecticut, USA

    Akiko Nishiyama & Maria Rubio

  3. Department of Anatomy, Hokkaido University Graduate School of Medicine, Sapporo, 060-8638, Japan

    Masahiro Fukaya

Authors
  1. Jennifer L Ziskin
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Akiko Nishiyama
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Maria Rubio
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Masahiro Fukaya
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. Dwight E Bergles
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Dwight E Bergles.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary Fig. 1

NMDA receptor expression by NG2+ cells in the corpus callosum. (PDF 196 kb)

Supplementary Fig. 2

Association of NG2+ cells with nerve terminals and nodes of Ranvier. (PDF 242 kb)

Supplementary Methods (PDF 67 kb)

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Ziskin, J., Nishiyama, A., Rubio, M. et al. Vesicular release of glutamate from unmyelinated axons in white matter. Nat Neurosci 10, 321–330 (2007). https://doi.org/10.1038/nn1854

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nn1854

This article is cited by

Search

Advanced search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing