Abstracts

Rationale: Proinflammatory cytokines, such as interleukin-1beta (il1b), have shown to be up-regulated in surgical specimens of pharmacoresistent patients with epilepsy as well as in experimental rodent models of seizure; however, the expression profile of this cytokine in zebrafish brain after seizure is unknown. In this study, we investigated the il1b transcript profile in immature and adult zebrafish brain after a seizure induced by Pentylenetratazole (PTZ). Methods: Zebrafish were maintained according to standard procedures and all experiments were approved by animal ethical committee/UNICAMP. Adult and larvae (7 days post fertilization) zebrafish were separated in Seizure (SG) and Control (CG) groups. Animals from SG group were individually exposed to 15mM PTZ (2-3min for adults and 20min for larvae). Animals from CG were exposed to same handling condition, but in normal bath water. A total of 6 samples were used for each group and age. A single adult sample was composed by pooling two brains and 20 heads were used to compose each larvae sample. At 12h, 24h and 48h after a seizure, animals were anesthetized and the brains were immediately isolated, frozen in N2(L) and total RNA was extracted by Trizol (Invitrogen). Reverse transcriptase quantitative-PCR amplifications were carried out in triplicates with efIa as endogenous control (TaqMan®, Applied Biosystems). The relative quantification (RQ) was calculated by the equation RQ=2 -ΔΔCT. Statistical analysis was performed by Kruskall-Wallis test. Results: The mean ± Standard Deviation results obtained were: (i) adult: CG12h 0.95±0.31; SG12h 0.84±0.19; CG24h: 0.75±0.23; SG24h: 0.76±0.27; CG48h 0.85±0.16; SG48h 0.99±0.41; (ii) immature: CG12h 1.84±0.46; SG12h 2.00±0.61; CG24h: 2.18±1.07; SG24h: 1.15±0.51; CG48h 2.5±0.58; SG48h 2.02±0.63. No statistical significance was found between CG and SG for both, adult and larvae (p≥0.05). Conclusions: This is the first study investigating il1b transcript profile in zebrafish brain after a PTZ-induced seizure.The results indicated that il1b transcript levels have a different pattern in zebrafish as compared to those described in rodent models of epilepsy. To better characterize the il1b transcript profile pattern in mature and immature zebrafish brain, studies are under way to explore the il1b expression pattern at 0.05h, 6h and 72h after PTZ induced-seizure.