Changes in Spontaneous firing patterns of cerebellar Purkinje cells in p75 knockout mice.
Changes in Spontaneous firing patterns of cerebellar Purkinje cells in p75 knockout mice.
复制标题
p75 敲除小鼠小脑浦肯野细胞自发放电模式的变化。
DOI：
10.1007/s12311-012-0439-6
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发表时间：
2013
期刊：
影响因子：
--
通讯作者：
Yoon,SungOk
中科院分区：
文献类型：
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作者：
Tian,Jinbin;Tep,Chhavy;Zhu,MichaelX;Yoon,SungOk
p75神经营养因子受体在发育中的神经系统中高度表达，并且是神经元存活、生长和突触传递所需的。在年轻小鼠中，p75存在于小脑的颗粒细胞和浦肯野细胞中。虽然p75已被牵连在几种神经元类型的神经元兴奋性的调制，它是否以及如何影响小脑浦肯野神经元的兴奋性仍不清楚。使用细胞外记录的自发放电的浦肯野神经元在小脑切片制备的野生型和p75基因敲除小鼠，我们测量的内在放电特性的快速突触阻滞剂的存在下，超过200浦肯野细胞，每个为期5分钟，为每个基因型。与野生型同窝仔相比，我们检测到p75−/−神经元的平均放电频率显著增加。在将紧张性放电与相位性放电细胞分离后，即，对于放电停顿时间超过300 ms的细胞，我们观察到这种变化主要来自相位放电细胞，并且可以通过5分钟记录期间放电/沉默比的增加和长停顿次数的减少来解释。我们的结论是，p75起着重要的作用，在调节的阶段性放电期间的自发放电的浦肯野细胞的放电到沉默的过渡。因此，p75对浦肯野细胞放电模式发挥调节功能，通过该功能，它可能在运动协调和其他小脑调节活动中起关键作用，因为浦肯野细胞代表小脑皮质的唯一神经元输出。
The p75 neurotrophin receptor is highly expressed in the developing nervous system and is required for neuronal survival, growth, and synaptic transmission. In young mice, p75 is present in both granular cells and Purkinje cells of the cerebellum. Although p75 has been implicated in modulation of neuronal excitability in several neuronal types, whether and how it affects the excitability of cerebellar Purkinje neurons remained unclear. Using extracellular recordings of spontaneous firing of Purkinje neurons in cerebellar slices prepared from wild type and p75 knockout mice, we measured intrinsic firing properties in the presence of fast synaptic blockers of more than 200 Purkinje cells, each for a period of 5 min, for each genotype. We detected a significant increase in the mean firing frequency in p75−/−neurons comparing to the wild type littermates. Upon separating tonically firing from phasically firing cells, i.e., cells with firing pauses of longer than 300 ms, we observed that the change mainly arose from phasic firing cells and can be explained by an increase in the firing/silence ratio and a decrease in the number of long pauses during the 5-min recording period. We conclude that p75 plays an important role in regulating the firing-to-silence transition during the phasic firing period of the spontaneous firing of Purkinje cells. Thus, p75 exerts a modulatory function on Purkinje cell firing patterns, through which it may act as a key player in motor coordination and other cerebellum-regulated activities since Purkinje cells represent the sole neuronal output of the cerebellar cortex.