Affiliations: Department of Experimental Ophthalmology, University
Eye Hospital Münster, Domagkstr. 15, D – 48149 Münster,
Germany
Note: [] Corresponding author: S. Thanos, Department of Experimental
Ophthalmology, University Eye Hospital Münster, Domagkstraße 15, D
– 48149 Münster, Germany. Tel.: +49 251 8356915; Fax: +49 251
8356916; E-mail: solon@uni.muenster.de
Abstract: Purpose: Following optic nerve damage, retinal ganglion cells (RGCs)
fail to regenerate their axons and soon undergo apoptosis. However, many RGCs
survive axotomy and regenerate lengthy axons after a lens injury (LI). If the
cut optic nerve is re-sutured, RGC axons grow into the distal part of the optic
nerve and reach their natural targets within the thalamus and midbrain. In this
study, we check time-dependence and extent of restoration of flash visual
evoked potentials (FVEPs) to examine the functional relevance of the
regenerated retinogeniculate pathway. Methods: The optic nerve in adult rats was cut and re-sutured. The
lens was injured transsclerally using a pointed glass capillary. FVEPs were
measured starting at the time point of surgery, and then repeatedly up to an
age of several months. Results: Detectable FVEPs appeared approximately ten weeks after the
surgery, and their amplitudes increased during the next months to reach
eventually 15–40% of their values before surgery. Conclusions: Partial restoration of FVEPs indicates that some
regenerating RGC axons have "bridged" the distance between the eye and the
central targets forming a functional re-connection of the corresponding RGC
with thalamic target neurones to elicit recordable activation of the visual
cortex
