Transitory gliosis in the CA3 hippocampal region in rats fed on a ketogenic diet

The ketogenic diet (KD) is a high-fat, low-protein and low-carbohydrate diet included as medical practice against seizure disorders, particularly in children refractory to conventional anti-epileptic drug treatment. However, the molecular basis of its therapeutic effect remains unclear. Considering the growing evidence for the importance of glial cells for neuronal development, survival and plasticity, we investigated astrocyte protein markers from KD fed rats, in different regions of hippocampus, a brain structure commonly involved in seizure disorders. We found a transitory increment in GFAP in the CA3 hippocampal region, but not in the CA1 or dentate gyrus (DG). This change was not accompanied by changes in S100B content or glutamine synthetase activity. In order to evaluate possible hippocampal involvement we investigated spatial-cognitive behavior using the water-maze task. No changes were observed. This transitory gliosis in CA3 could be related to, or precede, other associated changes proposed to be involved in the attenuation of seizure disorders. These data reinforce the importance of hippocampal astrocytes as cell targets during KD feeding.