Low-threshold calcium currents contribute to locomotor-like activity in neonatal mice
Low-threshold calcium currents contribute to locomotor-like activity in neonatal mice
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DOI：
10.1152/jn.00583.2011
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发表时间：
2012-01-01
影响因子：
2.5
通讯作者：
Masino, Mark A.
中科院分区：
文献类型：
--
作者：
Anderson, Tatiana M.;Abbinanti, Matthew D.;Masino, Mark A.
马萨诸塞州马西诺Rm。低阈值钙电流有助于新生小鼠的运动样活动。神经生理学杂志107：103-113,2012。2011年10月12日首次出版；DOI：10.1152/jn.00583.2011。-在这项研究中，我们研究了低阈值钙电流[i-Ca(T)]对新生小鼠运动相关活动的贡献。具体地说，研究了I-Ca(T)在化学诱导的化学诱导的运动样活动中的作用，该活动在分离的整个脊髓和由同源异型盒基因HB9标记的遗传上不同的脊髓腹内侧间神经元群体中。在分离的整个脊髓中，在低阈值钙通道阻滞剂存在的情况下，周期频率降低，这表明I-Ca(T)在产生节律性、运动性活动的网络中起作用。此外，我们使用HB9中间神经元作为模型来研究细胞对应用低阈值钙通道阻滞剂的反应。在转基因HB9：：增强型绿色荧光蛋白新生小鼠的横切片制备中，当TTX阻断快速、棘波介导的突触传递时，N-甲基-D-天冬氨酸诱导的HB9中间神经元的膜电位振荡也随着镍的应用而减慢。电压钳实验和免疫标记实验证实，位于脊髓腹内侧部的HB9中间神经元分别表达了I-Ca(T)和通道。综上所述，这些结果支持T型钙电流在化学诱发的虚构运动活动中的全网络节律产生中发挥重要作用。
RM, Masino MA. Low-threshold calcium currents contribute to locomotor-like activity in neonatal mice. J Neurophysiol 107: 103-113, 2012. First published October 12, 2011; doi: 10.1152/jn.00583.2011.-In this study, we examined the contribution of a low-threshold calcium current [I-Ca(T)] to locomotor-related activity in the neonatal mouse. Specifically, the role of I-Ca(T) was studied during chemically induced, locomotor-like activity in the isolated whole cord and in a genetically distinct population of ventromedial spinal interneurons marked by the homeobox gene Hb9. In isolated whole spinal cords, cycle frequency was decreased in the presence of low-threshold calcium channel blockers, which suggests a role for I-Ca(T) in the network that produces rhythmic, locomotor-like activity. Additionally, we used Hb9 interneurons as a model to study the cellular responses to application of low-threshold calcium channel blockers. In transverse slice preparations from transgenic Hb9:: enhanced green fluorescent protein neonatal mice, N-methyl-D-aspartate-induced membrane potential oscillations in identified Hb9 interneurons also slowed in frequency with application of nickel when fast, spike-mediated, synaptic transmission was blocked with TTX. Voltage-clamp and immunolabeling experiments confirmed expression of I-Ca(T) and channels, respectively, in Hb9 interneurons located in the ventromedial spinal cord. Taken together, these results provide support that T-type calcium currents play an important role in network-wide rhythm generation during chemically evoked, fictive locomotor activity.