QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

HOME  |   SEARCH  |   ARCHIVE  |   SUBSCRIBE  |   CONTACT  |   HELP

The Journal of Neuroscience, May 24, 2006, 26(21):5684-5697; doi:10.1523/JNEUROSCI.4993-05.2006

This Article Full Text Full Text (PDF) Supplemental data Submit an eLetter Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (16) Citing Articles via Google Scholar Google Scholar Articles by Kimura, Y. Articles by Higashijima, S.-i. Search for Related Content PubMed PubMed Citation Articles by Kimura, Y. Articles by Higashijima, S.-i.

 Previous Article  |  Next Article 

Cellular/Molecular
alx, a Zebrafish Homolog of Chx10, Marks Ipsilateral Descending Excitatory Interneurons That Participate in the Regulation of Spinal Locomotor Circuits

Yukiko Kimura, Yasushi Okamura, and Shin-ichi Higashijima

National Institutes of Natural Sciences, Okazaki Institute for Integrative Bioscience, and National Institute for Physiological Sciences, Myodaiji Okazaki, Aichi 444-8787, Japan

Correspondence should be addressed to Shin-ichi Higashijima, National Institutes of Natural Sciences, Okazaki Institute for Integrative Bioscience, Higashiyama 5-1, Myodaiji, Okazaki, Aichi 444-8787, Japan. Email: shigashi{at}nips.ac.jp

Recent molecular genetic studies suggest that the expression of transcription factors in the developing spinal cord helps determine the morphological and physiological properties of neurons. Using the zebrafish preparation, we have examined the properties of neurons marked by alx, a zebrafish homolog of mammalian Chx10. We performed morphological and physiological studies using transgenic zebrafish expressing fluorescent reporter constructs in cells that had at any time point expressed alx (alx neurons). Our data reveal that zebrafish alx neurons are all ipsilateral descending neurons that are positive for vesicular glutamate transporter 2, suggesting that they are glutamatergic excitatory interneurons. Patch recordings show that earlier-born neurons are active during stronger movements such as escapes and fast swimming (strong movement class), whereas later-born ones are involved in sustained weak swimming (weak movement class). Paired recordings between alx neurons and motoneurons show that neurons of the strong movement class make frequent monosynaptic excitatory connections onto motoneurons. Thus, neurons of this class are likely premotor interneurons that regulate motoneuron activity during escapes and fast swimming. We also show the existence of a monosynaptic connection between an alx neuron of the weak movement class and a motoneuron. Collectively, our data demonstrate that alx marks ipsilateral descending neurons that are involved in the regulation of motoneuron activity during forms of locomotion, such as escape and swimming.

Key words: neural development; locomotion; spinal cord; zebrafish; Chx10; GFP

---

Received Nov. 22, 2005; revised April 14, 2006; accepted April 15, 2006.

Correspondence should be addressed to Shin-ichi Higashijima, National Institutes of Natural Sciences, Okazaki Institute for Integrative Bioscience, Higashiyama 5-1, Myodaiji, Okazaki, Aichi 444-8787, Japan. Email: shigashi{at}nips.ac.jp

This article has been cited by other articles:

				A. Berkowitz Physiology and Morphology of Shared and Specialized Spinal Interneurons for Locomotion and Scratching J Neurophysiol, June 1, 2008; 99(6): 2887 - 2901. [Abstract] [Full Text] [PDF]

				K. Asakawa, M. L. Suster, K. Mizusawa, S. Nagayoshi, T. Kotani, A. Urasaki, Y. Kishimoto, M. Hibi, and K. Kawakami Genetic dissection of neural circuits by Tol2 transposon-mediated Gal4 gene and enhancer trapping in zebrafish PNAS, January 29, 2008; 105(4): 1255 - 1260. [Abstract] [Full Text] [PDF]

				J. P. Gabriel, R. Mahmood, A. M. Walter, A. Kyriakatos, G. Hauptmann, R. L. Calabrese, and A. El Manira Locomotor Pattern in the Adult Zebrafish Spinal Cord In Vitro J Neurophysiol, January 1, 2008; 99(1): 37 - 48. [Abstract] [Full Text] [PDF]

				W.-C. Li, B. Sautois, A. Roberts, and S. R. Soffe Reconfiguration of a Vertebrate Motor Network: Specific Neuron Recruitment and Context-Dependent Synaptic Plasticity J. Neurosci., November 7, 2007; 27(45): 12267 - 12276. [Abstract] [Full Text] [PDF]

				M. G. Del Barrio, R. Taveira-Marques, Y. Muroyama, D.-I. Yuk, S. Li, M. Wines-Samuelson, J. Shen, H. K. Smith, M. Xiang, D. Rowitch, et al. A regulatory network involving Foxn4, Mash1 and delta-like 4/Notch1 generates V2a and V2b spinal interneurons from a common progenitor pool Development, October 1, 2007; 134(19): 3427 - 3436. [Abstract] [Full Text] [PDF]

				T. Sato, T. Hamaoka, H. Aizawa, T. Hosoya, and H. Okamoto Genetic Single-Cell Mosaic Analysis Implicates ephrinB2 Reverse Signaling in Projections from the Posterior Tectum to the Hindbrain in Zebrafish J. Neurosci., May 16, 2007; 27(20): 5271 - 5279. [Abstract] [Full Text] [PDF]

				S. A. Hutchinson, S. E. Cheesman, L. A. Hale, J. Q. Boone, and J. S. Eisen Nkx6 proteins specify one zebrafish primary motoneuron subtype by regulating late islet1 expression Development, May 1, 2007; 134(9): 1671 - 1677. [Abstract] [Full Text] [PDF]

Home  |   Search  |   Archive  |   Subscribe  |   Contact  |   Help