癫痫大鼠海马神经元生化分子的同步辐射显微红外光谱成像研究
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摘要
癫痫是影响所有年龄段的慢性脑功能障碍,主要特征为整个或局部脑区神经元异常同步化高频群集动作电位发放。利用神经毒素海人藻酸(KA)立体定位注射入大鼠海马,诱导大鼠产生癫痫持续状态,建立颞叶癫痫大鼠模型。应用同步辐射显微光谱和同步辐射显微光谱成像分析癫痫持续状态发作后24小时的颞叶癫痫大鼠海马角(CA)1区神经元生物化学分子的胞内浓度和分布是否改变。结果显示反映蛋白质二级结构的酰胺Ⅰ在1 655cm-1的振动频率和属于脂类功能集团的2 800～3 000cm-1振动频率,在正常对照大鼠海马CA1神经元胞体内呈高浓度分布,但在癫痫大鼠海马CA1神经元胞体,反映蛋白质二级内呈低浓度分布,并且以细胞核分布浓度最低,但在神经元胞体外围分布浓度相对较高。属于核酸集团的1 055～1 054cm-1 PO2反对称拉伸振动在正常和癫痫大鼠海马CA1神经元胞体内分布趋势没有差异,都在胞体内呈高浓度分布,尤其在细胞核分布浓度最高。对属于酰胺Ⅰ的吸收频率进行二级导数分析显示癫痫海马神经元的酰胺Ⅰ相对于正常对照多出1个1 653cm-1附近的负峰。以上结果提示在发生癫痫持续发作后海马神经元生物化学分子的细胞分布会出现变化。
Epilepsy is a common chronic neurological disorder which is characterized by the occurrence of unprovoked and recurrent spontaneous seizures.Kainic acid(KA),a neurotoxin,was stereotaxically injected into the right hippocampus of rats to induce the post-status epilepticus(SE)model of temporal lobe epilepsy.Then the neurons in CA1 subregion of the hippocampus in the post-SE rats were detected by synchrotron radiation based-Fourier transform infrared microspectroscopy(SR-FTIR)at24hour after status epilepticus,determining the distribution and concentration of main biochemical molecules in the epileptic neurons.The infrared imaging of the biological molecules showed that the protein and lipid functional groups(bands at:1 655cm-1,2 800～3 000cm-1)were mainly localized in the cell body of the control CA1 neuron,whereas exhibited intracellular low concentration but high concentration in the region surrounding the cell body in the epileptic neurons of the hippocampal CA1 subregion.Moreover,the nucleic acid functional groups(bands at:1 055～1 054cm-1)were mainly located in the cell body of neurons in the control and epilepsy rats,and there was no significant difference in the distribution and concentration of the nucleic acid functional groups between the control and epileptic neurons.Additionally,the secondary derivative spectra for amideⅠ(assigned to 1 655cm-1)in the CA1 neurons showed that there was an additional negative peak near 1 653cm-1 in the epileptic hippocampus compared to the control neuron.These findings suggested that the disorders of biochemical composition in the hippocampal neurons in epilepsy rats emerge earlier than their morphological damages.
Epilepsy is a common chronic neurological disorder which is characterized by the occurrence of unprovoked and recurrent spontaneous seizures.Kainic acid(KA),a neurotoxin,was stereotaxically injected into the right hippocampus of rats to induce the post-status epilepticus(SE)model of temporal lobe epilepsy.Then the neurons in CA1 subregion of the hippocampus in the post-SE rats were detected by synchrotron radiation based-Fourier transform infrared microspectroscopy(SR-FTIR)at24hour after status epilepticus,determining the distribution and concentration of main biochemical molecules in the epileptic neurons.The infrared imaging of the biological molecules showed that the protein and lipid functional groups(bands at:1 655cm-1,2 800～3 000cm-1)were mainly localized in the cell body of the control CA1 neuron,whereas exhibited intracellular low concentration but high concentration in the region surrounding the cell body in the epileptic neurons of the hippocampal CA1 subregion.Moreover,the nucleic acid functional groups(bands at:1 055～1 054cm-1)were mainly located in the cell body of neurons in the control and epilepsy rats,and there was no significant difference in the distribution and concentration of the nucleic acid functional groups between the control and epileptic neurons.Additionally,the secondary derivative spectra for amideⅠ(assigned to 1 655cm-1)in the CA1 neurons showed that there was an additional negative peak near 1 653cm-1 in the epileptic hippocampus compared to the control neuron.These findings suggested that the disorders of biochemical composition in the hippocampal neurons in epilepsy rats emerge earlier than their morphological damages.
引文
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[3] Delorenzo R J,Sun D A,Deshpande L S.Pharmacol.Ther.,2005,105(3):229.
[4] Loscher W.Prog.Neurobiol.,1997,53(2):239.
[5] Remy S,Beck H.Brain,2006,129(1):18.
[6] Ellis D I,Dunn W B,Griffin J L,et al.Pharmacogenomics,2007,8(9):1243.
[7] Petibois C,Deleris G.Trends.Biotechnol.,2006,24(10):455.
[8] Miller L M,Dumas P.Biochim.Biophys.Acta,2006,1758(7):846.
[9] Nasse M J,Walsh M J,Mattson E C,et al.Nat.Methods,2011,8(5):413.
[10] Gianoncelli A,Vaccari L,Kourousias G,et al.Sci.Rep.,2015,5:10250.
[11] Petibois C,Deleris G.Cell.Biol.Int.,2005,29(8):709.
[12] Bandekar J.Biochim.Biophys.Acta,1992,1120(2):123.
[13] Krimm S,Bandekar J.Adv.Protein.Chem.,1986,38:181.
[14] Sahu R K,Mordechai S,Manor E.Biopolymers,2008,89(11):993.
[15] Dumas P,Miller L M.J.Biol.Phys.,2003,29(2-3):201.