title: Possible role of dentate gyrus in greneration of rat temporal lobe epilepsy induced by electrical stimulation.
abstract: Possible role of the dentate gyrus (DG) and the hippocampus (HPC) in temporal lobe epileptogensis was investigated in an electrogenic model of rat epilepsy. Chronic tetani (60 Hz, 0.4-0.6 mA. 2 s) were administered once daily for 7 days to the right dorsal hippocampus (DHPC) or the right DG. Animal behavior was observed and depth electro-graphic seizures and T(2)-weighted magnetic resonance images (T(2)-WI) were measured. Results indicated that the frequency of primary wet dog shakes (WEDS) in the DG-stimulated rats was much lower than that in the DHPC-stimulated rats (P<0.05). The mean maximal wave-amplitude in DG electrographs was also much lower than that in HPC electrographs (P<0.05). The oscillations proportion of DHPC electrographs increased after DHPC-tetanization (from 2/9 up to 7/9 rats). T(2)-WI hyperintensity in the lateral ventricle area was detected only in the DHPC-tetanized rats, not in the DG-tetanized rats (P<0.05). These results suggest that the DG acts as a filtering site in the entorhinal cortex-HPC neuronal circuitry and its dysfunction causes damage to the HPC and the generation of temporal lobe epilepsy.
authors.affiliation: Department of Physiology, Medical College, Wuhan University, Wuhan 43007l.
authors.forename: X R
authors.initials: XR
authors.lastname: Zhang
authors.forename: D
authors.initials: D
authors.lastname: Han
authors.forename: Y F
authors.initials: YF
authors.lastname: Tang
authors.forename: M L
authors.initials: ML
authors.lastname: Liu
authors.forename: S J
authors.initials: SJ
authors.lastname: Yin
mesh_terms: D000818:Animals; D018891:Dentate Gyrus / Q000503:physiopathology*; D004558:Electric Stimulation / Q000009:adverse effects; D004567:Electrodes, Implanted; D004833:Epilepsy, Temporal Lobe / Q000209:etiology / Q000503:physiopathology*; D006624:Hippocampus / Q000503:physiopathology*; D008279:Magnetic Resonance Imaging; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley