MORPHOLOGICAL PLASTICITY OF AXOTOMIZED RETINAL GANGLION-CELLS FOLLOWING INTRAVITREAL TRANSPLANTATION OF A PERIPHERAL-NERVE SEGMENT

During normal development of retinal ganglion cells when the axons are growing, transient dendritic spines have been observed. Similar dendr itic spine-like processes are also exhibited by retinal ganglion cells undergoing axonal regeneration into a peripheral nerve grafted to the damaged optic axons. Here we show, using the intracellular injection of Lucifer Yellow, that when a segment of peripheral nerve is transpla nted to the vitreous body, a procedure which induces ectopic sprouting of axon-like processes from the cell bodies and dendrites of some ret inal ganglion cells, similar spine-like processes appear on the dendri tes of cells with ectopic sprouts. Quantitative analysis indicated tha t there were significant changes with posttransplantation survival tim e in the distributions of spine-like processes and axon-like processes on these sprouting retinal ganglion cells following the intravitreal transplantation of a piece of peripheral nerve. The remodelling of the spine-like processes and axon-like processes correlated with one anot her suggesting that plastic changes can occur in certain dendritic sub compartments independent of the growth activity of the other dendritic subcompartments.