Expression of the P/Q (Cav2.1) calcium channel in nodose sensory neurons and arterial baroreceptors.
Expression of the P/Q (Cav2.1) calcium channel in nodose sensory neurons and arterial baroreceptors.
复制标题
P/Q (Cav2.1) 钙通道在结状感觉神经元和动脉压力感受器中的表达。
DOI：
10.1016/j.neulet.2012.05.026
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发表时间：
2012
影响因子：
2.5
通讯作者：
Kunze,DianaL
中科院分区：
文献类型：
--
作者：
Tatalovic,Milos;Glazebrook,PatriciaA;Kunze,DianaL
结状感觉神经元（包括压力感受器神经元亚群）中的主要钙电流是N型通道Cav2.2。它也是负责脑干孤束核中突触前末梢递质释放的主要钙通道。P/Q通道Cav2.1是负责哺乳动物突触处递质释放的另一种主要钙通道，仅占一般感觉神经元群体中总钙电流的15-20%，并且对突触前末端处的递质释放贡献较小。在本研究中，我们鉴定了最大的结状神经元（电容> 50 pF）的亚群，令人惊讶的是，其中Cav2.1占总钙电流的50%以上，与其余的群体不同。与这些电生理数据一致，抗Cav2.1抗体标记在结状神经节切片中的大神经元亚组中更多地被膜界定。在中枢神经系统的其他突触中报道的数据将突触信息传递中的不同角色分配给P/Q型与N型钙通道。该研究提出了一种可能性，即与其他中枢突触的高保真度传输相关的P/Q通道在这组大型有髓鞘感觉传入神经中具有类似的功能，包括动脉压力感受器，其中高频规则放电模式发出压力脉冲信号。这与无髓鞘纤维的不规则低频放电形成对比，无髓鞘纤维构成感觉群体的大部分，并且在突触传递中利用N型通道。
The predominant calcium current in nodose sensory neurons, including the subpopulation of baroreceptor neurons, is the N-type channel, Cav2.2. It is also the primary calcium channel responsible for transmitter release at their presynaptic terminals in the nucleus of the solitary tract in the brainstem. The P/Q channel, Cav2.1, the other major calcium channel responsible for transmitter release at mammalian synapses, represents only 15–20% of total calcium current in the general population of sensory neurons and makes a minor contribution to transmitter release at the presynaptic terminal. In the present study we identified a subpopulation of the largest nodose neurons (capacitance > 50 pF) in which, surprisingly, Cav2.1 represents over 50% of the total calcium current, differing from the remainder of the population. Consistent with these electrophysiological data, anti-Cav2.1 antibody labeling was more membrane delimited in a subgroup of the large neurons in slices of nodose ganglia. Data reported in other synapses in the central nervous system assign different roles in synaptic information transfer to the P/Q-type versus N-type calcium channels. The study raises the possibility that the P/Q channel which has been associated with high fidelity transmission at other central synapses serves a similar function in this group of large myelinated sensory afferents, including arterial baroreceptors where a high frequency regular discharge pattern signals the pressure pulse. This contrasts to the irregular lower frequency discharge of the unmyelinated fibers that make up the majority of the sensory population and that utilize the N-type channel in synaptic transmission.