Postnatal Maturation of Glutamatergic Inputs onto Rat Jaw-closing and Jaw-opening Motoneurons
Postnatal Maturation of Glutamatergic Inputs onto Rat Jaw-closing and Jaw-opening Motoneurons
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大鼠闭颌和张颌运动神经元谷氨酸能输入的出生后成熟
DOI：
10.1016/j.neuroscience.2021.11.016
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发表时间：
2022
期刊：
影响因子：
3.3
通讯作者：
Inoue Tomio
中科院分区：
文献类型：
--
作者：
Nakamura Shiro;Kajiwara Risa;Noguchi Tsuyoshi;Nakayama Kiyomi;Mochizuki Ayako;Dantsuji Masanori;Sarkar Avijite Kumer;Inoue Tomio
运动神经元支配下颌闭合肌和下颌张开肌，在咀嚼、吮吸和吞咽等口面部行为中起着关键作用。这些运动神经元可以改变其生理特性，通过出生后的时期，在此期间，喂养行为从吸吮咀嚼转变;然而，这些神经元的发育变化的功能突触特性仍然未知。因此，我们探讨了出生后的变化，在大鼠出生后早期发育过程中的运动神经元，支配下颌闭合和下颌张开肌肉系统的神经元的突触传递。我们测量了由非NMDA受体（non-NMDA mEPSCs）和NMDA受体介导的咬肌和二腹肌运动神经元的微型兴奋性突触后电流（mEPSCs）。咬肌运动神经元的非NMDA mEPSCs的振幅、频率和上升时间在出生后2-5、9 -12和14 -17天年龄组中保持不变，而衰减时间随着年龄的增长而显著减少。P2-5咬肌运动神经元的NMDA mEPSC的特性更占主导地位，随着神经元的成熟而减少。咬肌运动神经元的NMDA mEPSC的衰减时间也随发育而显著缩短。电刺激三叉神经上区诱发的NMDA/non-NMDA EPSCs比例在P2-5咬肌运动神经元中较高，然后向P14-17下降。与咬肌运动神经元相反，二腹肌运动神经元在整个出生后发育过程中，非NMDA和NMDA EPSC的特性没有变化。我们的研究结果表明，发育模式的非NMDA和NMDA受体介导的输入不同的下颌关闭和下颌打开运动神经元，可能与各自的运动神经元在出生后发育的摄食行为的不同作用。
Motoneurons that innervate the jaw-closing and jaw-opening muscles play a critical role in oro-facial behaviors, including mastication, suckling, and swallowing. These motoneurons can alter their physiological properties through the postnatal period during which feeding behavior shifts from suckling to mastication; however, the functional synaptic properties of developmental changes in these neurons remain unknown. Thus, we explored the postnatal changes in glutamatergic synaptic transmission onto the motoneurons that innervate the jaw-closing and jaw-opening musculatures during early postnatal development in rats. We measured miniature excitatory postsynaptic currents (mEPSCs) mediated by non-NMDA receptors (non-NMDA mEPSCs) and NMDA receptors in the masseter and digastric motoneurons. The amplitude, frequency, and rise time of non-NMDA mEPSCs remained unchanged among postnatal day (P)2–5, P9–12, and P14–17 age groups in masseter motoneurons, whereas the decay time dramatically decreased with age. The properties of the NMDA mEPSCs were more predominant at P2–5 masseter motoneurons, followed by reduction as neurons matured. The decay time of NMDA mEPSCs of masseter motoneurons also shortened remarkably across development. Furthermore, the proportion of NMDA/non-NMDA EPSCs induced in response to the electrical stimulation of the supratrigeminal region was quite high in P2–5 masseter motoneurons, and then decreased toward P14–17. In contrast to masseter motoneurons, digastric motoneurons showed unchanged properties in non-NMDA and NMDA EPSCs throughout postnatal development. Our results suggest that the developmental patterns of non-NMDA and NMDA receptor-mediated inputs vary among jaw-closing and jaw-opening motoneurons, possibly related to distinct roles of respective motoneurons in postnatal development of feeding behavior.