Dietary omega-3 fatty acids modify ganglion cell function

¹ Optometry and Vision Sciences, The University of Melbourne, Cnr Keppel & Cardigan St, Carlton, Victoria, 3053, Australia
² Optometry and Vision Sciences, The University of Melbourne, Melbourne, Victoria, Australia

^* To whom correspondence should be addressed. E-mail: ngc{at}unimelb.edu.au.

	Abstract

AIM: Dietary induced deficiencies in Omega-3 (-3) fatty acids are well known to alter photoreceptor function. In this study we consider the broader functional changes in a diversity of retinal neurons. METHODS: Sprague-Dawley dams were fed either -3 sufficient (-3⁺, n = 21) or deficient (-3^-, n = 19) diets 5 weeks prior to conception with pups continued on the mothers diet. After 20 weeks of age, electroretinograms (ERGs) were recorded using protocols that isolate separate cellular generators, including; photoreceptors (PIII), ON-bipolar cells (PII), and ganglion/amacrine cells (STR). At brightest energies rod and cone responses were isolated with a paired flash paradigm. Retinal tissue (-3⁺, n = 5; -3^-, n = 5) was harvested at 23 weeks of age for fatty acid assays with thin layer and gas liquid chromatography. RESULTS: Omega-3 deficiency caused 48.6% decrease in total retinal docosahexaenoic acid (DHA). This change induced a significant amplitude decreases only in the rod PII (-8.2%) and pSTR components (-27.4%) with widespread delays in all signals (PIII 5.7%, PII 13.6%, pSTR 7.6%, nSTR 8.3%). Omega-3 deficiency yielded its greatest effects on signals originating in the inner retina (pSTR). CONCLUSIONS: Increasing dietary -3 has beneficial effects across the retina, with the greatest improvement occurring in ganglion cell function.

Key Words: fatty acids, ganglion cell, electroretinography