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Principal Investigator:
Schwob, James, M.D., Ph.D.
George A. Bates Professor of Histology and Chair Department of Anatomy
and Cellular Biology
Department
of Anatomy & Cellular Biology
Tufts University
School of Medicine
136 Harrison Avenue
Boston, Massachusetts 02111
Office Phone:
(617)636-6626
Lab Phone:
(617)636-2418
FAX:
(617)636-0823
EMail
Address:
jim.schwob@tufts.edu
Program
in Cellular and Molecular Biology
Sackler School
Medical
School
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Targeted
axon growth:
| Our studies on the specification
of axon growth are using molecular and cell biological approaches
to examine how an Ig superfamily member, termed OCAM or mammalian
Fasciclin II, of the NCAM-Fasciclin II family of cell adhesion molecules,
directs targeted axon growth during olfactory development and regeneration.
In the peripheral olfactory system, the molecule is synthesized at
high levels by neurons in the ventrolateral part of the epithelium
(a functionally distinct part of the epithelium) and expressed heavily
on the derived axons and their terminals in the region of the olfactory
bulb that they target. We are studying the cell biological mechanisms
by which this molecule contributes to directed axon growth by manipulating
expression levels in vitro and in vivo. In addition, we contrast the
pattern of reinnervation that develops after two forms of lesion --
nerve transection vs. direct epithelial injury -- where we find that
axons are grossly mistargeted during regrowth after nerve damage,
but not after peripheral injury. However, even
after peripheral injury, the regeneration of the precise receptotopy
that normally characterizes the projection onto the glomeruli of the
bulb requires the sparing of some pre-existing
axons of the same odorant receptor type, suggesting that the fasciculation
of like-fibers is critical to axon targeting in this setting. Thus,
we are investigating the ancillary cells and molecules that are differentially
affected by the two forms of lesion. Finally, we are using differential
expression of OCAM/mamFas II and of the various members of the odorant
receptor gene family as a wedge into the generation of neuronal diversity
in this system, by taking advantage of the transplantation paradigm. |
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| Program
in Cell, Molecular, and Developmental Biology
136 Harrison Avenue, 5th Floor
Boston, MA 02111 617-636-6685
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