A Comparative Study Of Frontotemporal And Cerebellar Cortex Convulsant Threshold And Nerve Damage

Objective:Through electrical stimulation of rat cerebral cortex we will measure its convul sions threshold and comparing of the convulsions threshold in different parts of cort ex.At last we will observe the pathophysiological changes after the electrical stimu lation of the different parts of cortex.Method:Select health female SD rats and its weight varies from 180 g to 220 g.We plac e electrodes to make models in frontal cortex,temporal lobe cortex and cerebellar cortex and as stimulating groups,control group only places electrode and does not stimulate.Using a direct current electric stimulation by 2 times a day,then stimulati ng frontal cortex,temporal lobe cortex and cerebellar cortex.After stimulation grou p convulsions threshold value is stable,under the quiet and free state,recording the EEG of rats before and after electrical stimulation the brain cortex,At last executi ng the rats,observating the changes hippocampus neurons damage situation with Ni ssl's staining.Results:1.At the start of experiment,three stimulation group rats' cortex convulsions th reshold are high,the threshold group of frontal lobe group fluctuates about 1100 uA,threshold value fluctuates in the temporal lobe group about 1200 uA,but the cerebel lum group' is 2100 uA.Through longer duration of stimulation,the threshold of threegroups continue to decrease,eventually the threshold stops to decrease in a stable baseline.But its baseline are not identical,the threshold of frontal lobe group fluct uates in about 520 ?A,the temporal lobe group' stabilizes at about 440?A,the ce rebellum group' stabilizes at about 1300?A.Through the single factor analysis of v ariance,after the comparison among groups' stable convulsions threshold,the compa rison of P of the frontal lobe and temporal lobe group beyond 0.05,the P between cerebellum group and frontal lobe group is less than 0.05,the P between cerebell um group and temporal lobe group is less than 0.05 too.2.With extended of stimulation time,hippocampal CA3 area of the stimulation group appear different degree change,such as neuron disordered arrangement,neur on loss phenomenon,compared with control group.The neurons average number of control group are 36,the frontal lobe ‘s are 22,the temporal lobe's are 17,the c erebellum group's are 26.The neurons number of stimulation group are reduced,and the neurons number among them are statistically difference(P<0.05).3.The symptoms and the performance of electrical stimulation cerebellar cortex is different from the frontal and temporal lobe cortex's.The frontal and temporal lo be epilepsy showed a typical epileptiform convulsion,such as nodding,must,limbs and systemic rigidity-clonus behavior,however,cerebellum group characterizes by sys temic tetanic convulsion and running,jumping,etc.Conclusion:1.For the same intensity of electrical stimulation,temporal lobe and frontal lo be cortex is more sensitive to electrical stimulation than cerebellar cortex and easier formation of pathological channel,the susceptibility to electrical stimulate between the temporal lobe and frontal lobe are much the same;2.Through the rat cortex electrical stimulation,pathological changes may involv e the hippocampus,damage in hippocampus of temporal lobe stimulation group is t he most serious than frontal lobe cortex,and cerebellar cortex stimulation group ha s minimum effect on the hippocampus.