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Growth cone and dendrite dynamics in zebrafish embryos: early events in synaptogenesis imaged in vivo

Abstract

We used time-lapse fluorescence microscopy to observe the growth of Mauthner cell axons and their postsynaptic targets, the primary motor neurons, in spinal cords of developing zebrafish embryos. Upon reaching successive motor neurons, the Mauthner growth cone paused briefly before continuing along its path. Varicosities formed at regular intervals and were preferentially associated with the target regions of the primary motor neurons. In addition, the postsynaptic motor neurons showed highly dynamic filopodia, which transiently interacted with both the growth cone and the axon. Both Mauthner cell and motor neurons were highly active, each showing motility sufficient to initiate synaptogenesis.

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Figure 1: Illustration of the Mauthner cell–primary motor neuron system.
Figure 2: Time-lapse imaging of the Mauthner cell growth cone.
Figure 3: Time-lapse imaging of primary motor neurons and filopodia dynamics.
Figure 4: Simultaneous two-photon imaging of the Mauthner growth cone and primary motor neurons.
Figure 5: Projections of the Mauthner axon and sets of primary motor neurons.
Figure 6: Formation of an axonal varicosity.
Figure 7: Interaction of dendritic filopodia with the Mauthner axon.

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References

  1. Yasargil, G. M. & Diamond, J. Startle-response in teleost fish: an elementary circuit for neural discrimination. Nature 220, 241–243 ( 1968).

    Article  CAS  Google Scholar 

  2. Diamond, J. in Fish Physiology Vol. 5 (eds. Hoar, W. S. & Randall, D. J.) 265–346 (Academic, New York, 1971).

    Google Scholar 

  3. Kimmel, C. B., Powell, S. L. & Metcalfe, W. K. Brain neurons which project to the spinal cord in young larvae of the zebrafish. J. Comp. Neurol. 205 , 112–127 (1982).

    Article  CAS  Google Scholar 

  4. Mendelson, B. Development of reticulospinal neurons of the zebrafish. I. Time of origin . J. Comp. Neurol. 251, 160– 171 (1986).

    Article  CAS  Google Scholar 

  5. Mendelson, B. Development of reticulospinal neurons of the zebrafish. II. Early axonal outgrowth and cell body position. J. Comp. Neurol. 251, 172–184 (1986).

    Article  CAS  Google Scholar 

  6. Metcalfe, W. K., Mendelson, B. & Kimmel, C. B. Segmental homologies among reticulospinal neurons in the hindbrain of zebrafish larva. J. Comp. Neurol. 251, 147–159 (1986).

    Article  CAS  Google Scholar 

  7. Fetcho, J. R. & Faber, D. S. Identification of motoneurons and interneurons in the spinal network for escapes initiated by the Mauthner cell in goldfish. J. Neurosci. 8, 4192– 4213 (1988).

    Article  CAS  Google Scholar 

  8. Myers, P. Z. Spinal motoneurons of the larval zebrafish. J. Comp. Neurol. 236, 555–561 (1985).

    Article  CAS  Google Scholar 

  9. Myers, P. Z., Westerfield, M. & Eisen, J. S. Development and axonal outgrowth of identified motoneurons in the zebrafish. J. Neurosci. 6, 2278– 2289 (1986).

    Article  CAS  Google Scholar 

  10. Westerfield, M., McMurray, J. V. & Eisen, J. S. Identified motoneurons and their innervation of axial muscles in the zebrafish. J. Neurosci. 6, 2267–2277 (1986).

    Article  CAS  Google Scholar 

  11. Eisen, J. S., Myers, P. Z. & Westerfield, M. Pathway selection by growth cones of identified motoneurones in live zebra fish embryos. Nature 320, 269–271 (1986).

    Article  CAS  Google Scholar 

  12. Liu, D. W. & Westerfield, M. Function of identified motoneurones and co-ordination of primary and secondary motor systems during zebra fish swimming. J. Physiol. (Lond.) 403, 73– 89 (1988).

    Article  CAS  Google Scholar 

  13. Celio, M. R., Gray, E. G. & Yasargil, G. M. Ultrastructure of the Mauthner axon collateral and its synapses in the goldfish spinal cord. J. Neurocytol. 8, 19–29 (1979).

    Article  CAS  Google Scholar 

  14. Yasargil, G. M. & Sandri, C. Topography and ultrastructure of commisural interneurons that may establish reciprocal inhibitory connections of the Mauthner axons in the spinal cord of the tench, Tinca tinca L. J. Neurocytol. 19, 111– 126 (1990).

    Article  CAS  Google Scholar 

  15. Harris, W. A., Holt, C. E. & Bonhoeffer, F. Retinal axons with and without their somata, growing to and arborizing in the tectum of Xenopus embryos: a time-lapse video study of single fibres in vivo. Development 101, 123–133 (1987).

    Article  CAS  Google Scholar 

  16. O'Rourke, N. A. & Fraser, S. E. Dynamic changes in optic fiber terminal arbors lead to retinotopic map formation: an in vivo confocal microscopic study. Neuron 5, 159–171 (1990).

    Article  CAS  Google Scholar 

  17. O'Rourke, N. A., Cline, H. T. & Fraser, S. E. Rapid remodeling of retinal arbors in the tectum with and without blockade of synaptic transmission. Neuron 12, 921–934 (1994).

    Article  CAS  Google Scholar 

  18. Witte, S., Stier, H. & Cline, H. T. In vivo observations of timecourse and distribution of morphological dynamics in Xenopus retinotectal axon arbors. J. Neurobiol. 31, 219–234 (1996).

    Article  CAS  Google Scholar 

  19. Wu, G. Y. & Cline, H. T. Stabilization of dendritic arbor structure in vivo by CaMKII. Science 279, 222–226 (1998).

    Article  CAS  Google Scholar 

  20. Kaethner, R. J. & Stuermer, C. A. Dynamics of terminal arbor formation and target approach of retinotectal axons in living zebrafish embryos: a time-lapse study of single axons. J. Neurosci. 12, 3257–3271 ( 1992).

    Article  CAS  Google Scholar 

  21. Dynes, J. L. & Ngai, J. Pathfinding of olfactory neuron axons to stereotyped glomerular targets revealed by dynamic imaging in living zebrafish embryos. Neuron 20, 1081– 1091 (1998).

    Article  CAS  Google Scholar 

  22. Shoji, W., Yee, C. S. & Kuwada, J. Y. Zebrafish semaphorin Z1a collapses specific growth cones and alters their pathway in vivo. Development 125, 1275–1283 (1998).

    Article  CAS  Google Scholar 

  23. Dailey, M. E. & Smith, S. J. The dynamics of dendritic structure in developing hippocampal slices. J. Neurosci. 16, 2983–2994 (1996).

    Article  CAS  Google Scholar 

  24. Ziv, N. E. & Smith, S. J. Evidence for a role of dendritic filopodia in synaptogenesis and spine formation. Neuron 17, 91–102 (1996).

    Article  CAS  Google Scholar 

  25. Saito, Y. et al. Developing corticorubral axons of the cat form synapses on filopodial dendritic protrusions. Neurosci. Lett. 147, 81–84 (1992).

    Article  CAS  Google Scholar 

  26. Fiala, J. C., Feinberg, M., Popov, V. & Harris, K. M. Synaptogenesis via dendritic filopodia in developing hippocampal area CA1. J. Neurosci. 18, 8900–8911 (1998).

    Article  CAS  Google Scholar 

  27. Saito, Y., Song, W.-J & Murakami, F. Preferential termination of corticorubral axons on spine-like dendritic protrusions in developing cat. J. Neurosci. 17, 8792–8803 (1997).

    Article  CAS  Google Scholar 

  28. Honig, M. G. & Hume, R. I. Fluorescent carbocyanine dyes allow living neurons of identified origin to be studied in long-term cultures. J. Cell Biol. 103, 171–187 (1986).

    Article  CAS  Google Scholar 

  29. Kimmel, C. B., Ballard, W. W., Kimmel, S. R., Ullmann, B. & Schilling, T. F. Stages of embryonic development of the zebrafish. Dev. Dyn. 203, 253– 310 (1995).

    Article  CAS  Google Scholar 

  30. Luo, Y., Raible, D. & Raper, J. A. Collapsin: a protein in brain that induces the collapse and paralysis of neuronal growth cones. Cell 75, 217–227 (1993).

    Article  CAS  Google Scholar 

  31. Kolodkin, A. L. et al. Fasciclin IV: sequence, expression, and function during growth cone guidance in the grasshopper embryo. Neuron 9, 831–845 (1992).

    Article  CAS  Google Scholar 

  32. Saint-Amant, L. & Drapeau, P. Time course of the development of motor behaviors in the zebrafish embryo. J. Neurobiol. 37, 622–632 ( 1998).

    Article  CAS  Google Scholar 

  33. Westerfield, M. The Zebrafish Book (Univ. of Oregon Press, 1995).

  34. Maletic-Savatic, M., Malinow, R. & Svoboda, K. Rapid dendritic morphogenesis in CA1 hippocampal dendrites induced by synaptic activity. Science 283, 1923–1927 (1999).

    Article  CAS  Google Scholar 

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Acknowledgements

Susan Pike conducted initial work on this project. We thank S. Pike and faculty members of the MBL Neural Development and Genetics of the Zebrafish course (Woods Hole, Massachusetts) for help and advice. J.D.J. is a fellow of the Helen Hay Whitney Foundation. This work was supported by NIH grants to S.J.S.

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Correspondence to Stephen J. Smith.

Supplementary information

Video clips corresponding to Figs. 3, 4, 6 and 7

Supplementary Figure 3 (MPEG 503 KB)

Time-lapse imaging of primary motor neurons and filopodia dynamics. Video clips show brief time-lapse sequences of two RoP motor neurons.

Supplementary Figure 4 (MPEG 899 KB)

Simultaneous two-photon imaging of the Mauthner growth cone and primary motor neurons. The video sequence shows maximum-intensity projections from a representative time-lapse sequence during which an M-cell growth cone migrated past a CaP motor neuron. The growth cone was highly active and transiently interacted with the CaP cell, one of its synaptic partners. The growth cone moved past the CaP cell without collapsing, stalling or significantly altering its morphology.

Supplementary Figure 6 (MPEG 899 KB)

Formation of an axonal varicosity. This two-photon time-lapse sequence shows the formation of an axonal varicosity in close association with a CaP motor neuron. The images are maximum-intensity projections of image stacks displayed at five-minute intervals. Initially, the axon swelled, forming a large, elongated varicosity close to the CaP cell. Over time, the varicosity shrank and became more spherical. Throughout the time-lapse, there was extensive filopodia activity on the CaP cell near the developing varicosity.

Supplementary Figure 7 (MPEG 589 KB)

Interaction of dendritic filopodia with the Mauthner axon. This two-photon time-lapse sequence illustrates the interaction of a Mauthner growth cone with a RoP motor neuron as these two cells first came into contact. At the start of this time-lapse sequence, the Mauthner growth cone first reached the RoP ventral dendrite. Each image is a maximum-intensity projection of 14 sections collected at 1-mm steps. Numerous dendritic filopodia extended and retracted from the RoP ventral dendrite, many of which interacted transiently with the Mauthner axon. During this experiment, no stable cell-cell contacts were observed. Because a synapse will ultimately form between the Mauthner axon and the RoP ventral dendrite, it is possible that a filopodium may be responsible for initiating synaptogenic contact.

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Jontes, J., Buchanan, J. & Smith, S. Growth cone and dendrite dynamics in zebrafish embryos: early events in synaptogenesis imaged in vivo . Nat Neurosci 3, 231–237 (2000). https://doi.org/10.1038/72936

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