Excitatory Actions of Ventral Root Stimulation During Network Activity Generated by the Disinhibited Neonatal Mouse Spinal Cord
Excitatory Actions of Ventral Root Stimulation During Network Activity Generated by the Disinhibited Neonatal Mouse Spinal Cord
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DOI：
10.1152/jn.90740.2008
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发表时间：
2009-06-01
影响因子：
2.5
通讯作者：
O'Donovan, Michael J.
中科院分区：
文献类型：
--
作者：
Bonnot, Agnes;Chub, Nikolai;O'Donovan, Michael J.
Bonnot A，Chub N，Pujala A，O'Donovan MJ.前根刺激在新生小鼠脊髓去抑制后产生的神经网络活动中的兴奋作用。神经生理学杂志101：2995-3011，2009年。首次发表于2009年3月25日; doi：10.1152/jn.90740.2008。为了进一步了解运动神经元对脊髓网络功能的兴奋作用，我们研究了在新生小鼠脊髓中通过腹根（VR）刺激解除抑制的节律的夹带。在31/32个实验中，施加到VR的一系列简短刺激可靠地触发了爆发。当网络没有被去抑制时，携带去抑制爆发的同一根也可以产生类似运动的活动。在烟碱和毒蕈碱胆碱能拮抗剂中，VR刺激诱导节律的能力持续存在，但被AMPAR拮抗剂NBQX阻断。浴应用的I型mGluR 1受体拮抗剂CPCCOEt的背根和VR刺激的能力，夹带的去抑制的节奏和废除的能力，任何类型的刺激引起运动样活动。通过脊髓侧面的钙成像显示，VR刺激和自发发生的爆发伴随着一波活动，起源于腹侧和背侧传播。对L-5横切面进行成像显示，最早的VR诱发的视活动开始于腹外侧。伴随自发爆发的光学活动可能起源于腹外侧，腹内侧，或整个腹角的内侧范围或非常偶尔背侧。总的来说，我们的数据表明，VR刺激可以通过依赖于离子型和代谢型谷氨酸受体的激活的机制，夹带去抑制的脊髓网络活动和触发运动样活动。夹带的影响似乎是介导的腹外侧位于网络，也是活跃的自发发生的爆发。
Bonnot A, Chub N, Pujala A, O'Donovan MJ. Excitatory actions of ventral root stimulation during network activity generated by the disinhibited neonatal mouse spinal cord. J Neurophysiol 101: 2995-3011, 2009. First published March 25, 2009; doi: 10.1152/jn.90740.2008. To further understand the excitatory effects of motoneurons on spinal network function, we investigated the entrainment of disinhibited rhythms by ventral root (VR) stimulation in the neonatal mouse spinal cord. A brief train of stimuli applied to a VR triggered bursting reliably in 31/32 experiments. The same roots that entrained disinhibited bursting could also produce locomotor-like activity with a similar probability when the network was not disinhibited. The ability of VR stimulation to entrain the rhythm persisted in nicotinic and muscarinic cholinergic antagonists but was blocked by the AMPAR antagonist NBQX. Bath application of the type I mGluR1 receptor antagonist CPCCOEt reduced the ability of both dorsal root and VR stimulation to entrain the disinhibited rhythm and abolished the ability of either type of stimulation to evoke locomotor-like activity. Calcium imaging through the lateral aspect of the cord revealed that VR stimulation and spontaneously occurring bursts were accompanied by a wave of activity that originated ventrally and propagated dorsally. Imaging the cut transverse face of L-5 revealed that the earliest VR-evoked optical activity began ventrolaterally. The optical activity accompanying spontaneous bursts could originate ventrolaterally, ventromedially, or throughout the mediolateral extent of the ventral horn or very occasionally dorsally. Collectively, our data indicate that VR stimulation can entrain disinhibited spinal network activity and trigger locomotor-like activity through a mechanism dependent on activation of both ionotropic and metabotropic glutamate receptors. The effects of entrainment appear to be mediated by a ventrolaterally located network that is also active during spontaneously occurring bursts.