Research Description
I am interested in how the neurons and circuitry of the vertebrate
central nervous system are specified during development. In vertebrate
brains, neurons with similar long-distance connections are aggregated
into neural centers known as nuclei. Dozens of nuclei can be
distinguished in the brains of birds and mammals, and connections among
neurons in these brains are in essence connections targeted to different
nuclei. Viewed from this perspective, the problem of how neurons make
the correct connections with one another in early development is, for
studies of vertebrates, a problem of pattern formation: how are neurons
allocated to different nuclear fates? and how are nuclei formed?
My laboratory employs cellular and molecular techniques to ask how the
neurectoderm is organized at the time of nucleogenesis and to
investigate the developmental mechanisms responsible for pattern
generation and neuron cell-type specification. We identify emerging
nuclear patterns by the early organization of axonal connections and by
the expression of marker genes, including signaling molecules and
position-dependent transcription factors, isolated by motif-based
cloning strategies and genome database searches. cDNAs for these marker
genes are, in turn, candidates for misexpression experiments to probe
the genetic mechanisms that mediate the acquisition of neuronal identity
in brain nuclei.
Our research is carried out in chicks and mice. The chick
brain is accessible throughout development for fate mapping and cell
lineage studies, experimental embryology including tissue transplants,
and genetic manipulation by recombinant retrovirus infection and in ovo
electroporation. Research on the mouse embryo offers a broad range of
reverse genetic technologies and a number of established mutants. The
major effort of our current work is on two projects, how the nuclei of
the midbrain are generated in early development and how the patterning
of the cerebral cortex into areas and layers takes place.
Recent Publications on Midbrain
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Sanders, T.A., Lumsden, A. and Ragsdale, C.W. (2002)
Arcuate
plan of chick midbrain development.
J. Neuroscience 22, 10742-10750.
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Agarwala, S. and Ragsdale, C.W. (2002)
A
role for midbrain arcs in nucleogenesis.
Development 129, 5779-5788. |
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Agarwala, S., Sanders, T.A. and Ragsdale, C.W. (2001)
Sonic
Hedgehog control of size and shape in midbrain pattern formation.
Science 291, 2147-2150.
This article is reviewed in:
Hedgehog
patterns midbrain ARChitecture
by Machold and Fishell (2002).
TINS 25, 10-11.
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Recent Publications on Cerebral Cortex
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Assimacopoulos, S., Grove, E.A. and Ragsdale, C.W. (2003) Identification
of a Pax6-dependent epidermal growth factor family signaling source at
the lateral edge of the embryonic cerebral cortex. J. Neuroscience 23,
6399-6403.
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Ragsdale, C.W. and Grove, E.A. (2001)
Patterning
the mammalian cerebral cortex.
Current Opinion in Neurobiology 11, 50-58. |
Search PubMed for Dr. Ragsdale's publications
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