Pathological ,Physiological Status And Convulsive Threshold For The Convulsion Of Electric Stimulation Frontal Lobe ,Occipital Lobe And Temporal Lobe Cortex In Rat

Objectives: The purpose of this research is finding pathological,physiological status and convulsive threshold for the convulsion of electric stimulation frontal lobe,occipital lobe and temporal lobe cortex in rat. that is say , the different current intensity stimulate cerebral cortex ,the convulsant threshold of cerebral cortex how to change and the pathology of different part cerebral tissue .Methods: In this study determination of the threshold for convulsions is made by direct cortical stimulation in rats. The strong current stimulation (TPS) and the weak stimulation(TLS)are measured the convulsive threshold twice everyday, while recording convulsive threshold and subsequently examined histopathological changes.The frontal lobe model last 12 weeks, the occipital lobe and temporal lobe model last 10 weeksResults: (1) At the beginning of study , individual variations is large.The convulsive thresholds approached a constant level after a certain time, at the same time, individual variations became small. (2)The Pathological status change of rat brain tissue: In the strong current stimulation (TPS) of frontal lobe, hippocampal neurons degenerate at the forth week, occipital lobe neurons degenerate at the fifth week and temporal lobe neurons degenerate at the third week, The longer of the stimulation the more serious the neuron damaged which were showed as a significant decrease in the number of normal pyramidal cells. the weak stimulation (TLS)frontal lobe, hippocampal neurons degenerate lightly at at the fifth week, occipital lobe neurons degenerate lightly at the sixth week and temporal lobe neurons degenerate at the forth week. (3) At the end of study , the firing index of spike(sharp) waves after reaching TPS's significantly increased, that is to say, there was a significant change in the firing index of spike(sharp) waves when stimulation continued for more times.Conclusions:1,Pathological convulsive threshold is formed by more electric stimulation and pathological factors, the more electric stimulation and pathological factors, the faster Pathological convulsive threshold is formed.2,The pathological changs in hippocampus is serious ,the more electric stimulation duration,the more serious the pathological changs.3,The more electric stimulation,the more serious the pyramidal cells damage, but the pathological changs can reversible with the early intervention4,The temporal lobe is the most sensitive in the three lobes to pathological factors and the pathological changs is the most easy to form, the occipital lobe is the seconed sensitive...