alpha-SNS produces the slow TTX-resistant sodium current in large cutaneous afferent DRG neurons.
alpha-SNS produces the slow TTX-resistant sodium current in large cutaneous afferent DRG neurons.
复制标题
α-SNS 在大的皮肤传入 DRG 神经元中产生缓慢的 TTX 抵抗钠电流。
作者：
M. Renganathan;T. Cummins;W. Hormuzdiar;S. Waxman
在本研究中，我们使用感觉神经元特异性（SNS）钠通道基因敲除（-/-）小鼠来研究SNS钠通道是否在大（> - 40微米直径）皮肤传入背根神经节（DRG）神经元中产生慢Na（+）电流（“慢”）。以SNS野生型（+/+）小鼠为对照。逆行氟金标记允许皮肤传入神经元的明确鉴定。采用预脉冲失活分离快慢Na（+）电流。从SNS（+/+）小鼠分离的大皮肤传入神经元中，52%只表达快速失活的Na（+）电流（“快”），48%同时表达快速和慢速Na（+）电流。快、慢电流密度分别为0.90 +/- 0.12和0.39 +/- 0.16 nA/pF。快速Na（+）电流被300 nM河豚毒素（TTX）完全阻断，而慢Na（+）电流对300 nM TTX具有抗性，证实大皮肤DRG神经元中观察到的慢Na（+）电流具有TTX抗性（TTX- r）。SNS（-/-）小鼠皮肤大传入神经元中未检测到慢Na（+）电流；这些细胞仅表达快速Na（+）电流，并被300 nM的TTX阻断。SNS（-/-）神经元快速Na（+）电流密度为1.47 +/- 0。14 nA/pF，比SNS（+/+）小鼠高约60% （P < 0.02）。在小的c型神经元中观察到的低压激活的TTX-R Na（+）电流（“持续”）在SNS（+/+）或SNS（-/-）小鼠的大皮肤传入神经元中都不存在。这些结果表明，大皮肤传入DRG中TTX-R Na（+）慢电流是由SNS钠通道产生的。
In this study, we used sensory neuron specific (SNS) sodium channel gene knockout (-/-) mice to ask whether SNS sodium channel produces the slow Na(+) current ("slow") in large (>40 microm diam) cutaneous afferent dorsal root ganglion (DRG) neurons. SNS wild-type (+/+) mice were used as controls. Retrograde Fluoro-Gold labeling permitted the definitive identification of cutaneous afferent neurons. Prepulse inactivation was used to separate the fast and slow Na(+) currents. Fifty-two percent of the large cutaneous afferent neurons isolated from SNS (+/+) mice expressed only fast-inactivating Na(+) currents ("fast"), and 48% expressed both fast and slow Na(+) currents. The fast and slow current densities were 0.90 +/- 0.12 and 0.39 +/- 0.16 nA/pF, respectively. Fast Na(+) currents were blocked completely by 300 nM tetrodotoxin (TTX), while slow Na(+) currents were resistant to 300 nM TTX, confirming that the slow Na(+) currents observed in large cutaneous DRG neurons are TTX-resistant (TTX-R). Slow Na(+) currents could not be detected in large cutaneous afferent neurons from SNS (-/-) mice; these cells expressed only fast Na(+) current, and it was blocked by 300 nM TTX. The fast Na(+) current density in SNS (-/-) neurons was 1.47 +/- 0. 14 nA/pF, approximately 60% higher than the current density observed in SNS (+/+) mice (P < 0.02). A low-voltage-activated TTX-R Na(+) current ("persistent") observed in small C-type neurons is not present in large cutaneous afferent neurons from either SNS (+/+) or SNS (-/-) mice. These results show that the slow TTX-R Na(+) current in large cutaneous afferent DRG is produced by the SNS sodium channel.
DOI：
10.1073/pnas.94.4.1527
发表时间：
1997-02-18
影响因子：
11.1
作者：
ToledoAral, JJ;Moss, BL;Mandel, G
通讯作者：
Mandel, G
影响因子：
2.5
作者：
HONMOU, O;UTZSCHNEIDER, DA;KOCSIS, JD
通讯作者：
KOCSIS, JD