The retinas of adult teleost fish can regenerate
following injury, but little is known about the neuronal
integration of the visual scene that is performed by the
regenerated retina. Using goldfish retinal ganglion cells
(RGCs) as the experimental system, an evaluation of dendritic
arbor structure and passive electrotonic properties was
developed, the aim being to quantitatively test the hypothesis
that native and regenerated RGC dendritic arbors have similar
structural and modeled electrotonic attributes. Fractal
dimension was chosen as the descriptor of RGC dendritic
arbor complexity, and the arbors' transfer function
magnitudes were estimated using an electrically passive,
equivalent-circuit analysis. For both native and regenerated
RGCs, arbors qualitatively judged to be simple tended to
have lower fractal dimension values than arbors judged
to be more complex. All cells had similar cut-off frequencies,
and for random stimulation of greater than 25% of an RGC's
population of dendritic tips, there was a positive correlation
between fractal dimension and transfer function magnitude.
Some regenerated RGCs had abnormally long primary dendrites,
but neither the distributions of fractal dimension values,
nor the estimated transfer function magnitudes, were significantly
different between native and regenerated RGCs. The results
appear to support the hypothesis that structural and modeled
electrotonic attributes of regenerated goldfish RGCs are
similar to those of native RGCs, suggesting that regenerated
RGCs may restore normal visual function.