Expression Of NT-3 After Seizures In Temporal Lobe Epilepsy And Hippocampal Mossy Fiber Sprouting

Objective To investigate the potential relation of abnormal neural circuits and quantitive changes of neurotrophin-3 in hippocampus of experimental temporal epilepsy rats.To investigate the effects of NT-3 antisense oligonucleotide on abnormal neural circuits such as injury of hippocampus neuron and mossy fiber sprout and to explore the role of NT-3 in experimental temporal epilepsy models of rats.Methods Create experimental TLE models of rats by injecting kainic acid in lateral ventricle of adult rats.1,inject NT-3 sense and antisense oligonucleotide and phosphate buffer saline in lateral ventricle 36 hours later when models were created.Then measure the expression of NT-3 in hippocampus of model rats by immunohistochemistry at the 2nd,4th and 7th day.2.inject NT-3 sense and antisense oligonucleotide and physiological saline in lateral ventricle at the 2nd,7th and 10th day.MSF and synapse restitution in hippocampus were Neo-Timm silver stained and examined by light microscope and electron microscope.Results Expression level of NT-3 in hippocampus dentate gyrus of KA-inducing TLE rats decreased decreased and then recoveried to infranormal in first 7 days.MSF was obvious in hippocampus at 2ed week. Expression level of NT-3 was effectively down and MSF was to a higher extent after injecting NT-3 antisense oligonucleotide.Histopathologic examination for granulosa cell and inner plexiform layer in dentate gyrus of rats with electron microscope showed:silver stained synapses were seldom,examined in normal group but could be examined in model group,which existed in synaptic cleft or synaptic vesicle.The majority of these synapses were axo-spinous synapses,part of those were the axo-dendritic synapse and axosomatic synapse.The differences of ethological reflect among groups were inconspicuous.Conclusion Expression level of NT-3 in hippocampus dentate gyrus of KA-inducing TLE rats decreased and then recoveried to infranormal in first 7 days with MSF developing.MSF aggravated when NT-3 antisense oligonucleotide was injected in lateral ventricle.The inhibitory action of NT-3 on MFS possibly due to excitatory synapse remodeling and excitability enhances in neural circuits.