Electroencephalographic activity in neonatal ventral hippocampus lesion in adult rats

A neonatal ventral hippocampal lesion (NVHL) in rats has been commonly used as a neurodevelopmental model to mimic schizophrenia-like behaviors. Recently, we reported that NVHL resulted in dendritic retraction and spine loss in pyramidal neurons of the prefrontal cortex (PFC). In addition, the hippocampus and PFC are important structures in the regulation of the electroencephalographic (EEG) activity. Patients with PFC lesions show deficits in the EEG activity. This study aimed to determine whether the EEG activity was altered in NVHL rats. In addition, we also analyzed the locomotor activity induced by a novel environment and exploratory behavior using the hole-board test. Consistent with the behavioral findings, the EEG analysis of the cortical regions showed that the NVHL rats displayed a lower power in cortical bands. At 1-8 Hz, 9-14 Hz, and 15-30 Hz bands, our findings showed a decrease in the absolute power of the parietal and occipital cortices recordings. In addition, the NVHL rats also showed a reduction in the exploratory behavior tested using the hole-board test. In conclusion, this study demonstrated that the EEG activity was reduced in adult NVHL rats and suggests that this may play a role in the behavioral changes observed in this neurodevelopmental model of schizophrenia.