998V Poster Online - Virtual Posters
Wednesday April 06, 4:00 PM - 7:00 PM

Authors:
Patrick Kuebler ¹; Anelise Hutson ²; Masashi Tabuchi ²; Daniel Kuebler ¹

Affiliations:
1) Franciscan University of Steubenville, Steubenville, OH; 2) Case Western Reserve University School of Medicine, Cleveland, OH

Keywords:
e. epilepsy; m. mechanosensation

There is an increasing amount of evidence that dietary and metabolic alterations can help reduce seizure susceptibility. The seizure-susceptible Drosophila bang-sensitive (BS) mutants represent a good model system for investigating the link between diet, metabolism, and seizure activity. The BS mutants exhibit seizure-like activity (SLA) and paralysis following a variety of stimuli including mechanical vortexing. Previous work demonstrated that feeding the BS mutants standard media supplemented with a commercial ketogenic dietary mix (10% w/v) could eliminate the seizure-like activity and paralysis seen in these mutants. Given the mix of lipids in the supplement, this study examined the ability of specific polyunsaturated omega fats to alleviate the seizure-paralysis phenotype in one of the BS mutants, technical knockout (tko). The tko flies were fed 10% (w/v) sucrose-only media supplemented with one of two omega-3 fatty acids, eicosapentaenoic acid and docosahexaenoic acid, or one omega-6 fatty acid, arachidonic acid. The omega fatty acids were added at a final concentration of 25 µg/ml of media and 1-2 day old tko male flies were reared in the media for 3 days prior to testing for bang sensitivity. All three of the omega fatty acids eliminated the SLA and paralysis normally seen in tko flies following mechanical shock. Following the 3-day exposure to the omega fatty acids, the flies were then switched back to standard media for ten days and retested for bang-sensitivity. Following this period of feeding on normal media, the flies still did not exhibit SLA and more than 90% of the flies did not exhibit paralysis. This indicates the ability of the omega fatty acids to rescue the phenotype was maintained even when the flies were subsequently removed from the diet.
To investigate changes in gene expression associated with the feeding of omega fatty acids, RNA was extracted from the heads of tko flies fed 1) docosahexaenoic acid (25 µg/ml), 2) arachidonic acid (25 µg/ml), and 3) control sugar-only media. The Affymetrix GeneChip Drosophila Gene 1.0 ST Array was then used to perform whole transcriptome analysis of these fly heads. When compared to flies on the control diet, the data demonstrated that a number of ribosomal proteins were highly upregulated in fly heads following both omega fatty acid supplementation diets. Given that previous researchers have seen alterations in ribosomal protein levels in dendrites and axons following cellular changes, the increases seen here may be associated with synaptogenesis and neural alterations that modify excitability of the tko nervous system.