[Abstract Title]. - Society for Neuroscience

Topic: A.04.i. Dendritic growth and branching
Support: NIH grants (JC, MML and DRC)
Research to Prevent Blindness (DRC and MML)
Knights Templar Research Grant (XL)
Research to Prevent Blindness (DRC and MML)
That Man May See (DRC)
Title: Neurotrophin-3 regulates early neonatal development of retinal ganglion cell dendrites
Authors: *X. LIU 1,2,3 , M. L. ROBINSON 6 , A. M. SCHREIBER 2 , V. WU 2 , M. M. LAVAIL 2,3,4 ,
J. CANG 1 , D. R. COPENHAGEN 2,3,5 ;
1 Neurobio. and Physiol., Northwestern Univ., Evanston, IL; 2 Ophthalmology, 3 Program in
Neurosci., 4 Anat., 5 Physiol., Univ. of California San Francisco, San Francisco, CA; 6 Zoology,
Miami Univ., Oxford, OH
Abstract: Purpose: To investigate the role of Neurotrophin-3 (NT-3) in the maturation of neural
retina in mouse. Methods: Transgenic mice expressing NT-3 driven by the αA-crystallin
promoter in the lens were crossed with Thy-1-YFP transgenic mice. Confocal Z-stack images of
YFP-expressing retinal ganglion cells (RGCs) were collected to examine their dendritic
structure. Results: During postnatal development, the initially diffuse dendritic arbors of RGCs
are refined into mono-laminated structures in the inner plexiform layer (IPL). The progressive
refinement of RGCs starts before eye-opening and continues for two weeks after eye-opening.
Overexpression of NT-3 in the eye accelerates RGC laminar refinement before eye-opening.
Furthermore, the dendritic arbors of ON-OFF RGCs expand mainly before eye-opening, and NT-
3 overexpression increases dendritic branching but inhibits dendritic elongation in ON-OFF
RGCs. In contrast, dendrites of ON RGCs expand both before and after eye-opening, and NT-3
overexpression does not affect dendritic maturation in these cells. In comparison, brain-derived
neurotrophic factor (BDNF) overexpression facilitates the formation of new branches in ON but
not ON-OFF RGCs. Taken together, our results suggest that NT-3 and BDNF play overlapping
roles in laminar refinement and distinct roles in dendritic arborization during RGC postnatal
development.
Disclosures: X. Liu , None; M.L. Robinson, None; A.M. Schreiber, None; V. Wu,
None; M.M. LaVail, None; J. Cang, None; D.R. Copenhagen, None.
Poster
231. Dendrite Growth and Branching: Signaling