The establishment of macaque models of temporal lobe epilepsy

Abstract

Objective To establish the animal model of temporal lobe epilepsy in macaques and to observe the changes of biological characteristics.Methods Kainic acid (KA) was injected into the right intra-hippocampus of macaques with the stereotacic technique.Video recording,iconology,hisopathology,and ultrastructural changes of the macaques were observed to evaluate the biological characteristics.Electrocorticography (EcoG)was used to detect the electrophysiological changes.Magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS)were performed.Then macaques were sacrificed and brains were removed for ultrastructural examination using electron microscopes after 3 months post-injection.Results Typical seizures were observed in the models.Epileptic discharge,such as spike,slow,spike-slow,and sharp appeared in electroencephalograms (EEG).Hippocampal sclerosis could be found by MRI and MRS.HE staining of samples from the macaques injected with KA showed neuronal loss,proliferation of glial cells,formation of glial scar,and hippocampal atrophy.Electron microscopic analysis of hippocampal tissues revealed pyknosis of neurons,depolymerization of part ribosomes,swollen mitochondrias,the abnormal reduction of rough endoplasmic reticulum,expansion of Golgi vesicles,swollen star-shaped cells,swollen axons in surrounding neurons,and mild perivascular edema.Conclusions The seizure patterns,imaging findings,and pathological changes suggest that this macaque model of epilepsy induced by KA has great resemblance to human temporal lobe epilepsy (TLE).Therefore,it can be used as a model for studying human temporal epilepsy. Key words: Temporal lobe epilepsy; Kainic acid; Stereotaxis; Models, animal; Macaques