Change And Significance Of Dopaminenergic Neurons In Rat Temporal Epilepsy

Part one Experiment Study of Dopaminenergic Neurons Transformation in Substantia Nigraof Temporal Epilepsy Animal Model ObjectiveTo establish animal model of temporal epilepsy in Spraque-Dawley(SD) rat and research the changes of praxiologh and electroencephalogram(EEG) in different time of temporal epilepsy; To study dopamine-energic neurons transformation in substantia nigra and discuss the relationship of each other. Materials and methods43 male SD rats were divided into 3 groups including blank control group; saline group and kainic acid group. saline (2uL)was injected in lateral ventricle of the saline operating rats,and kainic acid(5ug) was performed in the epilepsy rats.The changes of praxiologh and electroencephalogram were studied in different time after treatment and rats were killed at 0.5h, 2h, 12h, 24h and 3d. Dopamine-energic neurons in substantia nigra were qualitated by immunohistochemistry and semi-quantitated by marked cells.Correlation analysis was done between amplitudes of EEG waves and quantities of marked cells. ResultsBlank control group and saline group did not show the epilepsy paroxysm .The rats of kainic acid group however emerged the obvious epilepsy. The paroxysm occued at 10 munite after injecting kainic acid in lateral ventricle and reached the top at 1 hours following the injection, stopped at 3~6 hours. According to the Racine's epilepsy behavior grade ,the rats in KA group were in line with epilepsia model standard.Sharp ware, spike ware and spike-slow ware didn't emerged in blank control group and saline group, hi KA group epilepsy ware occurred at 10 minute after injection and manifested as middle and high amplitude of ware such as sharp ware and spike ware along with high frequency. The amplitude and frequency of epilepsy ware reached the top following epilepsy paroxysm at 1 hours and descented at 3~6 hours, disappeared at 12 hours.Three minutes' records of EEGs had been drawn out to be dealt with statistical analysis. The amplitude of EEG displayed alikely in any stage of time in saline group,but showed difference in KA group, from 1.449±0.205 mV before treatment to 3.877±0.165 mV at 2 hours after injection. The numerical values of amplitudes were analysised in one-way ANOVA,and resulted as F=47.396 and p=0.000.The difference is significant at the 0.01 level among the different stages of time in KA group. Quantitatives of dopamine-energic neurons in substantin nigra reduced along with epilepsy paroxysm at 0.5 hours, compaired with saline group, which showed significant difference (p=0.003). They last on reducing at 2~6 hours, and recovered to normal at 3 days, compaired with saline group, which didn't show significant difference (p>0.05). ConclusionInjecting kainic acid into lateral ventricle could built temporal epilepsy animal model. Dopamine-energic neurons number chang in substantin nigra occured with epileptic epilepsy paroxysm which resulted from kainic acid, it was implied that dopamine-energic neurons in substantin nigra probably took part in adjustment oftemporal epileptic seizure.Part TwoSignificance of dopaminenergic neurons changes in rat temporal epilepsy ObjectiveTo establish animal model of temporal epilepsy in Spraque-Dawley(SD) rat and research the effects that dopamine Dl antagonist SCH23390 and D2 antagonist Haloperidol take effect on temporal epilepsy by kainic in substantia nigra. methods30 male SD rats were divided into 5 groups including saline group ;kainic acid group; SCH23390 group;Haloperidol group and saline + KA group, saline (2uL)was injected in lateral ventricle of the saline operating rats,and kainic acid(5ug) was performed in the epilepsy rats, kainic acid(5ug) was injected in lateral ventricle and SCH23390,Haloperidol and saline was respectively injected in substantia nigra inSCH23390 group,Haloperidol group and saline + acid group. Observe the change of behavior and electroencephalogram in each group. Rats were killed at 5 days after injection, section of brain was marked by TUNEL so as to observe apoptosis of hippocampus neurons cell fluorescent detector. resultsSaline group did not show the epilepsy paroxysm . The paroxysm occued at 10 munite after injecting kainic acid in lateral ventricle and reached the top at 1 hours following the injection, stopped at 3~6 hours, hippocampus neurons cell apoptosis occurred after epilepsy paroxysm. Quantitatives of apoptosis cell increased significantly after Haloperidol injected in substantia nigra, compaired with kainic acidgroup, which showed significant difference (p < 0.01).Injection of SCH23390 did not perform the change of apoptosis cell and did not show significant difference compaired with kainic acid group (p>0.05) . ConclusionInjecting kainic acid into lateral ventricle could increased excitory amino acides, apoptosis of hippocampus neurons cell and germination of moss nerve fiber,which resulted in epilepsy parosysm.With dopaminenergic neurons injuried by KA , synthesis of dopamine had weakened and quantitatives of dopamine reduced significantly which led to descreased the conjugation with Dl and D2 recerptors.With binding with D2 receptor descreased ,excitory of D2 receptors depressed and the effect of inhibition on excitory animo acides reduced ,Ca2+ flew into cells and post-discharge time had been prolonged ,which promated the occurrence and development of epilepsy.