Abstracts

Rationale: A spontaneous mutant rat was identified and shows neurophysiological and behavioral characteristics of generalized epilepsy with absence seizures, involving regions such as hippocampus and somatosensorial cortex. The aim of the present study was to perform gene expression studies in tissue obtained from these animals with generalized epilepsy with absence seizures (GEASv). Methods: We obtained high-quality total RNA from the hippocampus (n=3) of the GEASv rat and control animals (n=3) with TRIzol (Invitrogen-Life Technologies). Gene expression analysis was performed using the GeneChip® Rat Genome 230 2.0 Array (Affymetrix™), which has complete coverage of the rat genome with over 30.000 transcripts. We used 5 µg of starting material in the One-cycle Target Labeling Protocol (Affymetrix™). Data was acquired by GeneChip Scanner 3000 (Affymetrix™) and analyzed using MAS5.0 expression measure. Statistical analysis was performed by t-test with p≤0.01 for detecting a significant difference between groups. Results: Comparison between GEASv and control animals identified 46 transcripts which were differently expressed. Among these we found genes related to transcription factors, homeostasis, signaling and nervous system development, such as Nrsn1, Hap1, Pdyn, Gpx and Rgs4. Conclusions: We found significant differences in gene expression in the GEASv rat which, after validation, will help in the molecular and genetic characterization of this new spontaneous epilepsy genetic rat model. Support: FAPESP and FFM-HCFMUSP