对侧腹外侧索强直刺激在脊髓运动神经元诱发的长时程增强

Long-term potentiation of synaptic transmission in motoneurons induced by tetanic stimulation in contralateral ventrolateral funiculus of neonatal rat spinal cord in vitro

目的:探讨强直刺激对侧腹外侧索(cVLF),在脊髓运动神经元(MN)能否诱发突触传递的长时程可塑性变化。方法:应用新生大鼠脊髓切片MN细胞内记录技术,观察强直刺激cVLF前后,在MN诱发的兴奋性突触后电位(EP-SP,即cVLF-EPSP)的变化。结果:对cVLF施加强直刺激,有2个MNs的cVLF-EPSPs幅度增大达基础值的120%以上,且维持至少30 min,可被定义为长时程增强(LTP,即cVLF-LTP)。另外,在1个有cVLF-LTP的MN,同时观察到同侧背根刺激诱发的EPSP出现长时程增强。结论:通过强直刺激cVLF,在新生大鼠脊髓MN可诱发出突触传递的LTP,并可伴有异突触的LTP现象。

Objective：To explore whether long-term plasticity of synaptic transmission could be induced in motoneuron （MN） after tetanic stimulation of contralateral ventrolateral funiculus （cVLF） of spinal cord slices. Methods ： The intracellular recordings were performed in MNs of neonatal rat spinal cord slices, with observing the change of excitatory postsynaptic potential （EPSP） induced by cVLF stimulus （i. e. cVLFEPSP） in MN before and after tetanic stimulation of cVLF. Results ： In 2 MNs, the amplitude of cVLF-EPSPs increased more than 120% of baseline and the increase lasted longer than 30 min after tetanic stimulation of cVLF, which could be referred to as long-term potentiation （LTP, i.e. cVLF-LTP）. Moreover, in one MN with cVLF-LTP, the long-term enlargement of EPSP induced by ipsilateral dorsal root stimu- lation （iDR-EPSP） was observed as well. Conclusion： Long-term potentiation of contralateral descending activation in MN of neonatal rat spinal cord slices can be induced by tetanic stimulation of cVLF as well as concurrent heterosynaptic LTP of iDR-EPSP.