目的：探讨α-氨基-3-羟基-5-甲基-4-异恶唑丙酸(AMPA)受体参与大鼠脊髓发育早期突触传递的生理学特点。方法选取胎龄17 d(E17, n=12)和20 d(E20, n=12)的Wistar大鼠以及新生7 d(P7, n=12)的Wistar大鼠共计36只。胸髓钙调蛋白依赖性蛋白激酶Ⅱ(CaMKⅡ)免疫荧光染色观察AMPA受体的分布，电生理平面微电极阵列记录技术(MED-64系统)检测AMPA受体参与突触传递的场兴奋性突触后电位(fEPSP)的变化。结果 E17大鼠脊髓灰质开始出现少量CaMKⅡ阳性神经元，E20、P7大鼠脊髓周围CaMKⅡ阳性神经元逐渐向内迁移，神经元的数量不断增多。电生理结果显示，E17、E20、P7大鼠诱发的fEPSP数量依次增多，并能够被6-氰基-7-硝基喹喔啉-2,3-二酮(CNQX)阻断，脊髓灰质内突触联系的空间网络范围显著减小(P<0.001)。结论 AMPA受体参与大鼠脊髓早期发育，并作为脊髓前角神经网络中功能性突触联系的主要兴奋型受体。%Objective To explore the physiological characteristics of synaptic transmission of anterior horn early development in thorac-ic spinal cord mediated byα-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors in rats. Methods 36 Wistar rats were divided into embryonic 17 days group (E17, n=12), embryonic 20 days group (E20, n=12) and postnatal 7 days group (P7, n=12). Immuno-fluorescent staining of calmodulin-dependent protein kinaseⅡ(CaMKⅡ) was used to test the distribution of AMPA receptors. Multi-elec-trode array technique (MED-64 system) was used to test the changes of field excitatory post-synaptic potential (fEPSP) of synaptic transmis-sion mediated by AMPA receptor. Results There was small amount of CaMKⅡ-positive neurons existing in gray matter of spinal cord at E17, CaMKⅡ-positive neurons migrated to the center, and the number of neurons became more and more in E20 and P7 rats. The number of evoked fEPSP gradually increased in rats from E17 to P7, and could be blocked by 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX). The range of synaptic connection in spinal cord gray matter significantly reduced (P<0.001). Conclusion AMPA receptors participate in the early development of spinal cord in rats and act as the main excitatory receptor of functional synaptic connection in neural network of ventricornu.
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