Review

Neuronal specification in the spinal cord: inductive signals and transcriptional codes

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Abstract

Neural circuits are assembled with remarkable precision during embryonic development, and the selectivity inherent in their formation helps to define the behavioural repertoire of the mature organism. In the vertebrate central nervous system, this developmental program begins with the differentiation of distinct classes of neurons from progenitor cells located at defined positions within the neural tube. The mechanisms that specify the identity of neural cells have been examined in many regions of the nervous system and reveal a high degree of conservation in the specification of cell fate by key signalling molecules.

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Acknowledgements

This article is for Julia Willis. I am grateful to many lab members, past and present, for their essential contributions to the ideas and work summarized here. S. Arber, J. Briscoe, A. Kania, S. Sockanathan and C. William made many helpful comments on the text and Kathy MacArthur and Ira Schieren provided expert help in its preparation. Work in the lab is supported by grants from the NIH, The Mathers Foundation, Project ALS and by the Howard Hughes Medical Institute. T.M.J. is an investigator of the Howard Hughes Medical Institute.

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Affiliations

  1. Howard Hughes Medical Institute, Center for Neurobiology and Behavior, Department of Biochemistry and Molecular Biophysics, Columbia University, New York, New York 10032, USA. tmj1@columbia.edu

    • Thomas M. Jessell

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Glossary

PROPRIOCEPTION

The part of the somatosensory system that relays information about trunk and limb position.

ROSTROCAUDAL

The axis of the vertebrate embryo that runs from head to tail. Also referred to as the anterior–posterior axis at early stages of neural development.

DORSOVENTRAL

The axis of the vertebrate embryo that runs from back to stomach.

PARAXIAL MESODERM

Mesodermal cells that derive from the segmental plate mesoderm that flanks the midline axial mesoderm.

PRIMITIVE STREAK

A group of cells in gastrula-stage chick and mouse embryos that actively ingress from the epiblast layer to form mesodermal cell types.

NEURAL PLATE

The initial group of columnar neuroepithelial cells that forms as a result of neural induction.