RRC ID 6218
Author McLean DL, Fetcho JR.
Title Spinal interneurons differentiate sequentially from those driving the fastest swimming movements in larval zebrafish to those driving the slowest ones.
Journal J Neurosci
Abstract Studies of neuronal networks have revealed few general principles that link patterns of development with later functional roles. While investigating the neural control of movements, we recently discovered a topographic map in the spinal cord of larval zebrafish that relates the position of motoneurons and interneurons to their order of recruitment during swimming. Here, we show that the map reflects an orderly pattern of differentiation of neurons driving different movements. First, we use high-speed filming to show that large-amplitude swimming movements with bending along much of the body appear first, with smaller, regional swimming movements emerging later. Next, using whole-cell patch recordings, we demonstrate that the excitatory circuits that drive large-amplitude, fast swimming movements at larval stages are present and functional early on in embryos. Finally, we systematically assess the orderly emergence of spinal circuits according to swimming speed using transgenic fish expressing the photoconvertible protein Kaede to track neuronal differentiation in vivo. We conclude that a simple principle governs the development of spinal networks in which the neurons driving the fastest, most powerful swimming in larvae develop first with ones that drive increasingly weaker and slower larval movements layered on over time. Because the neurons are arranged by time of differentiation in the spinal cord, the result is a topographic map that represents the speed/strength of movements at which neurons are recruited and the temporal emergence of networks. This pattern may represent a general feature of neuronal network development throughout the brain and spinal cord.
Volume 29(43)
Pages 13566-77
Published 2009-10-28
DOI 10.1523/JNEUROSCI.3277-09.2009
PII 29/43/13566
PMID 19864569
PMC PMC2796107
MeSH Action Potentials Animals Animals, Genetically Modified Biomechanical Phenomena Cell Size Interneurons / physiology* Luminescent Proteins / genetics Luminescent Proteins / metabolism Microscopy, Confocal Motor Activity / physiology Motor Neurons / physiology Neural Pathways / embryology Neural Pathways / growth & development Neural Pathways / physiology Neurogenesis Patch-Clamp Techniques Spinal Cord / embryology Spinal Cord / growth & development* Spinal Cord / physiology* Swimming / physiology* Time Factors Zebrafish / physiology*
IF 6.074
Times Cited 79
Zebrafish nns1(Tg(chx10:GFP))? nns2(Tg(chx10:Kaede))? rw0130a(Tg (Huc:Kaede))