Segregation of glutamatergic and cholinergic transmission at the mixed motoneuron Renshaw cell synapse.
Segregation of glutamatergic and cholinergic transmission at the mixed motoneuron Renshaw cell synapse.
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DOI：
10.1038/s41598-017-04266-8
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发表时间：
2017-06-22
影响因子：
4.6
通讯作者：
Ascher P
中科院分区：
文献类型：
--
作者：
Lamotte d'Incamps B;Bhumbra GS;Foster JD;Beato M;Ascher P
在新生小鼠中，运动神经元通过释放乙酰胆碱(ACh)和谷氨酸来兴奋Renshaw细胞。这两种神经递质激活两种类型的烟碱受体(，同构体α7受体和异构体α受体)以及两种类型的谷氨酸受体(AMPAR和NMDARs)。使用配对的记录，我们证实了单个运动神经元可以在单个突触后Renshaw细胞上释放两种递质。然后，我们证明了共同传播在成年动物中得到了保留。对小型EPSCs的动力学分析表明，AMPAR和NMDARs以及α7和α？？nAChRs的混合事件有量子释放，但没有证据表明mEPSC将nAChRs和GluRs联系在一起。对诱发的EPSCs进行的贝叶斯量化分析(BQA)表明，当尼古丁受体被阻断时，单个伦肖细胞上的功能接触数量减少了一半以上，证实了这两个神经递质系统是分离的。我们的观察可以解释，如果ACh和谷氨酸从共同的囊泡释放到空间分离的突触后受体簇上，但突触前胆碱能和谷氨酸释放部位的分离也是可能的。
In neonatal mice motoneurons excite Renshaw cells by releasing both acetylcholine (ACh) and glutamate. These two neurotransmitters activate two types of nicotinic receptors (nAChRs) (the homomeric α7 receptors and the heteromeric α*ß* receptors) as well as the two types of glutamate receptors (GluRs) (AMPARs and NMDARs). Using paired recordings, we confirm that a single motoneuron can release both transmitters on a single post-synaptic Renshaw cell. We then show that co-transmission is preserved in adult animals. Kinetic analysis of miniature EPSCs revealed quantal release of mixed events associating AMPARs and NMDARs, as well as α7 and α*ß* nAChRs, but no evidence was found for mEPSCs associating nAChRs with GluRs. Bayesian Quantal Analysis (BQA) of evoked EPSCs showed that the number of functional contacts on a single Renshaw cell is more than halved when the nicotinic receptors are blocked, confirming that the two neurotransmitters systems are segregated. Our observations can be explained if ACh and glutamate are released from common vesicles onto spatially segregated post-synaptic receptors clusters, but a pre-synaptic segregation of cholinergic and glutamatergic release sites is also possible.