EFFECT OF EXPERIMENTAL DIABETIC RETINOPATHY ON THE NON-IMAGE FORMING VISUAL SYSTEM

SANDE PH; DE ZAVALÍA N; BELFORTE NA; DORFMAN D; ROSENSTEIN RE; FERNANDEZ DC

Seattle

Congreso; The Association For Research In Vision And Ophthalmology (Arvo); 2013

Association For Research In Vision And Ophthalmology (Arvo)

Invest Ophthalmol Vis Sci 2013;54: E-Abstract 2695.© 2013 ARVO 2695?A0017 EFFECT OF EXPERIMENTAL DIABETIC RETINOPATHY ON THE NON-IMAGE FORMING VISUAL SYSTEM Pablo Sande1, Nuria de Zavalia1, Nicolas Belforte1, Damian Dorfman1, Ruth Rosenstein1 and Diego Fernandez1 1 Human Biochemistry/Sch of Med, University of Buenos Aires, Buenos Aires, Argentina Commercial Relationships: Pablo Sande, None; Nuria de Zavalia, None; Nicolas Belforte, None; Damian Dorfman, None; Ruth Rosenstein, None; Diego Fernandez, None Support: None Abstract Purpose:We investigated the non-image forming visual system in an advanced stage of experimental diabetes in rats. Methods:Male Wistar rats were injected (i.p.) with vehicle or streptozotocin. A group of animals was submitted to bilateral lensectomy. Retinal (ERG), and visual pathway (visual evoked potentials) function, the number of Brn3a(+) and melanopsin(+) RGC (immunohistochemistry), and melanopsin levels (Western Blot) were examined. The pupil light reflex (PRL) (after 30-s light flash), and light-induced c-Fos expression in the suprachiasmatic nuclei (SCN) were assessed. Anterograde transport was examined after an intravitreal injection of cholera toxin β-subunit, and circadian rhythms of general locomotor activity were registered in cages equipped with infrared detectors of motion. Results:After 15 weeks of diabetes induction, clear alterations in the visual function were observed. Concomitantly with a significant decrease in the number of Brn3a(+) RGC, no differences in the number of melanopsin(+) cells, melanopsin levels, and retinal projections to the SCN and the olivary pretectal nucleus were observed. However, a significant decrease in light induced c-Fos expression in the SCN was found. In diabetic animals, the afferent PLR and the locomotor activity pattern appear to be conserved, although a delay in the time needed to re-entrainment after a phase delay was observed. In diabetic animals, lensectomy reversed the alterations in c-Fos expression and in the locomotor activity rhythm. Conclusions:These results indicate that the neuronal substrate of the non-image forming visual system remained largely unaffected at advanced stages of diabetes and lensectomy, a relatively easy and safe surgery, could restore circadian alterations induced by diabetes. Keywords: 458 circadian rhythms ? 499 diabetic retinopathy ? 531 ganglion cells