Dietary omega-3 fatty acids and ganglion cell function.
OBJECTIVE
Diet-induced deficiencies in Omega-3 (omega-3) fatty acids are well known to alter photoreceptor function. In this study, the broader functional changes in a diversity of retinal neurons were considered.


METHODS
Sprague-Dawley dams were fed either omega-3-sufficient (omega-3(+), n = 21) or -deficient (omega-3(-), n = 19) diets 5 weeks before conception, with the pups continued on the mothers' diet. After 20 weeks of age, electroretinograms (ERGs) were recorded by using protocols that isolate separate cellular generators, including; photoreceptors (PIII), ON-bipolar cells (PII), and ganglion/amacrine cells (STR). At the brightest energies, rod and cone responses were isolated with a paired-flash paradigm. Retinal tissue (omega-3(+), n = 5; omega-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 a 48.6% decrease in total retinal docosahexaenoic acid (DHA). This change induced significant amplitude decreases only in the rod PII (-8.2%) and positive (p)STR components (-27.4%), with widespread delays in all signals (PIII 5.7%, PII 13.6%, pSTR 7.6%, and negative [n]STR 8.3%). Omega-3 deficiency exerted its greatest effects on signals originating in the inner retina (pSTR).


CONCLUSIONS
Increasing dietary omega-3 has beneficial effects across the retina, with the greatest improvement occurring in ganglion cell function.
Nguyen
Christine T O
CT
Department of Optometry and Vision Sciences, University of Melbourne, Parkville, Victoria, Australia.
Vingrys
Algis J
AJ
Bui
Bang V
BV
D000818:Animals; D002849:Chromatography, Gas; D002855:Chromatography, Thin Layer; D004042:Dietary Fats, Unsaturated / Q000008:administration & dosage*; D004281:Docosahexaenoic Acids / Q000378:metabolism; D004596:Electroretinography; D015525:Fatty Acids, Omega-3 / Q000008:administration & dosage*; D005231:Fatty Acids, Unsaturated / Q000032:analysis; D005260:Female; D008055:Lipids / Q000172:deficiency*; D010775:Photic Stimulation; D020419:Photoreceptor Cells, Vertebrate / Q000502:physiology*; D011247:Pregnancy; D051381:Rats; D017207:Rats, Sprague-Dawley; D012160:Retina / Q000378:metabolism; D051245:Retinal Bipolar Cells / Q000502:physiology; D012165:Retinal Ganglion Cells / Q000502:physiology*
D004042:Dietary Fats, Unsaturated; D015525:Fatty Acids, Omega-3; D005231:Fatty Acids, Unsaturated; D008055:Lipids; D004281:Docosahexaenoic Acids