Protein-caloric dietary restriction inhibits mossy fiber sprouting in the pilocarpine model of TLE without significantly altering seizure phenotype

Abstract

Given the known effects of undernutrition over protein synthesis, we promoted neonatal undernutrition to evaluate its effect over the neuroplasticity induced by the pilocarpine model of epilepsy and also over spontaneous seizure expression. A well-nourished group (WN), fed ad libitum rat chow diet, and an undernourished group (UN), fed 60% of the amount of diet consumed by a WN group, were submitted to status epilepticus (SE) through pilocarpine injection at 45 days of age. Thereafter, animals were behaviorally monitored for 6h daily to quantify seizures. On the 120th day, electroencephalography (EEG) was recorded and rats were sacrificed to measure proteins and glutamate release from hippocampus. Neo-Timm staining was used to detect mossy fiber sprouting. The results indicate no statistical difference in the latency for the first spontaneous recurrent seizure (SRS), in the number of daily SRS, or in EEG epileptiform activity duration between groups. However, PILO promoted more K+-stimulated glutamate release in the hippocampus slices from WN animals when compared to the UN group. It was also found a lower degree of mossy fibers sprouting in UN group. Data from this work, thus, indicate that the decreased neuroplasticity as currently measured does not directly impact on the manifestation of spontaneous seizures.