Abstract
Purpose::
Bipolar cells are responsible of transmitting light signals from photoreceptors to ganglion cells in the vertebrate retina. Their maturation process is not only important for establishing normal visual functions, but may also underlie the dendritic remodeling of ganglion cells during development. It has been shown that light deprivation affects synaptic connections of ganglion cells in the mammalian retina, but little is known about impacts of visual deprivation on bipolar cell development. This study was to examine morphological differentiation of bipolar cells in the rabbit retina under both normal and dark rearing conditions.
Methods::
To visualize developmental processes of bipolar cells, both Lucifer Yellow injection and the Diolistic gene gun method were used to label developing bipolar cells in the retinal slice preparation from P0 through P14.
Results::
Our results showed that immature bipolar cells can be found as early as P1-3 in the rabbit retina, and most characteristic bipolar cells can be identified in P4-6. Most importantly, we found that light deprivation causes a delay rather than a permanent arrest of the bipolar cell maturation. By eye opening at P10-11, both normal and dark reared rabbits have possessed adult-like bipolar cells.
Conclusions::
The results suggest that visual experience has a facilitating effect on morphological differentiation of bipolar cells, and early mature bipolar cells may provide light dependent signals to guide synaptic connections of ganglion cells in the inner retina.
Keywords: bipolar cells • development • retina