Efeito da suplementação lipídica dietética na atividade elétrica cerebral de ratos normais e submetidos ao status epilepticus

Abstract

The brain is an organ composed of about 60% of lipids. Among these the most important lipids are the phospholipids, which may present in its hydrophobic tail, saturated and unsaturated fatty acids and cholesterol. Changes in the proportions of these lipids may alter the physicochemical properties of the membranes of the cells of the nervous system. Thus, it is reasonable to infer that changes in the dietary lipid supply may alter brain function; these changes often entail changes in brain electrical activity. This study evaluated electrical and histological changes of the nervous system resulting from supplementation with unsaturated fatty acids (omega-3) and a hypercholesterolemic diet (HCD), in animals normal and submitted to status epilepticus. The electrical activity of the animals was registered by ECoG, in which was performed the power spectrum and calculated the average power for the most important brain rhythms, delta (0.5 - 4 Hz), theta (4 - 8 Hz), Alpha (8 - 14 Hz) and beta (12 - 30Hz). Electrophysiological analysis showed that lipid supplementation, both from omega-3 as HCD, caused an acceleration of brain electrical activity. During the status epilepticus the animals supplemented with HCD showed a excitability greater than the control group and that animals supplemented with omega-3, indicating a status epilepticus with greater severity for the group fed the HCD. Histological analysis showed that the status epilepticus caused injury in the areas CA1, CA2, CA3 and the dentate gyrus of the hippocampus, all of them showing severe neuronal death with intense vacuolization and disintegration of the cell layers. However, these lesions were not easily identified in animals supplemented with omega-3, revealing a protective effect of omega-3 in nerve cells during status epilepticus.