Purchase this article with an account.
A.J. Weber, C.D. Harman, S. Viswanathan; BDNF Enhances Ganglion Cell Function Following Optic Nerve Damage in the Cat . Invest. Ophthalmol. Vis. Sci. 2006;47(13):1569.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Pressure–induced axonal injury and retinal ganglion cell degeneration are hallmarks of glaucomatous neuropathy. Previously, we showed that intravitreal application of brain–derived neurotrophic factor (BDNF) not only helps to preserve retinal ganglion cell numbers following optic nerve injury, but that it also has a positive effect on the fine structural integrity of these neurons. The purpose of this study was to determine whether BDNF treatment also aids in preserving ganglion cell function.
Eight adult cats received a severe crush of the left optic nerve. Four received no treatment, 2 received an intravitreal injection of 30ug of BDNF at the time of the crush, and 2 received 90ug injections of BDNF. One week post–surgery, the cats were anesthetized with ketamine/xylazine, the pupils were dilated and accommodation blocked, the eyes were properly refracted, and pattern electroretinograms (PERG) were recorded in response to counter–phased square wave gratings (0.06 to 2 cpd; 1Hz modulation; 50cd/m2 mean luminance; 95% contrast). The amplitude of the negative potential was measured relative to baseline, or peak of the preceding positive potential when present.
For the normal eyes, the mean PERG amplitudes were maximal around 100ms following each contrast reversal, and decreased with increased spatial frequency. PERGs in the experimental eyes that received no treatment were, on average, 36–47% of the control eye responses, depending on stimulus spatial frequency. While the responses from eyes receiving 30ug treatments with BDNF were only slightly better than the no treatment condition (36–63% of control), the PERGs from eyes that received the 90 ug BDNF treatment ranged from 70 to 130% of the control responses.
The data indicate that, in addition to preserving the structural integrity of ganglion cells, BDNF also helps maintain their functional responsiveness. The tendency toward better responses with higher doses might reflect the greater effect higher doses appear to have on large ganglion cells, particularly those near central retina, as shown previously.
This PDF is available to Subscribers Only