Affiliations: School of Life Sciences, Lanzhou University, Lanzhou,
730000, PRC, China | Developmental Biology Center and Department of
Developmental and Cell Biology, University of California, Irvine, CA 92717,
USA | School of Life Sciences, Lanzhou University, Lanzhou,
730000, PRC, China
Abstract: Purpose: Growing axons express a number of proteins associated with
axonal growth which are thought to be critical for regeneration and sprouting.
Whether these proteins are expressed during injury-induced axonal remodeling is
tested in this paper. Methods: The posterior half of the adult goldfish
tectum was removed leaving the anterior half intact. This causes optic fibers
from nasal retina, which project to posterior tectum, to displace temporal
fibers from the anterior remnant and form a compressed retinotopic projection
of the entire retina onto the anterior tectum. Immunohistochemistry using an
antibody shown here to recognize growing and regenerating fibers in goldfish
was used to monitor optic fibers. Results: As expected, surgery induced
reactivity in the axotomized nasal axons peaking at 1 month which returned to
normal at 2 months when compression was completed. Unexpectedly, axons from
temporal retina showed no detectable reactivity even though they were induced
to grow anteriorly by the invading nasal fibers. Conclusions: Extensive
axonal remodeling and synaptic rearrangement can occur without reentering the
growth state associated with axonal growth and regeneration.
