Epidermal Merkel cells are mechanosensory cells that tune mammalian touch receptors.
Epidermal Merkel cells are mechanosensory cells that tune mammalian touch receptors.
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DOI：
10.1038/nature13250
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发表时间：
2014-05-29
期刊：
影响因子：
64.8
通讯作者：
Lumpkin, Ellen A.
中科院分区：
文献类型：
--
作者：
Maksimovic, Srdjan;Nakatani, Masashi;Baba, Yoshichika;Nelson, Aislyn M.;Marshall, Kara L.;Wellnitz, Scott A.;Firozi, Pervez;Woo, Seung-Hyun;Ranade, Sanjeev;Patapoutian, Ardem;Lumpkin, Ellen A.
触摸子通道，如颤动和压力，是由躯体感觉传入调节的，其末端特化提取触觉特征，并将其编码为具有独特活动模式的动作电位序列。非神经细胞是通过主动机制还是被动机制来调节触觉感受器，这一点还存在争议。末端特化被认为是类似于耳蜗基底膜的被动机械过滤器，它将复杂的声音分解成由机械感觉毛细胞传递的音调。皮肤特化只是被动的这一模型最近受到了挑战，因为表皮细胞表达感觉离子通道和神经递质；然而，缺乏直接证据表明表皮细胞兴奋触觉传入。表皮Merkel细胞显示感觉受体细胞的特征，并与缓慢适应的I型(SAI)传入进行“突触样”接触。这些复合体编码边缘和纹理等空间特征，定位于具有高触觉敏锐度的皮肤区域，包括胡须毛囊、指尖和触摸圆顶。在这里，我们展示了默克尔细胞在小鼠体内积极参与触摸接收。首先，默克尔细胞显示快速、触摸诱发的机械传导电流。其次，在完整皮肤上的光遗传学方法表明，默克尔细胞是触觉传入中持续动作电位放电的必要条件和充分条件。第三，来自没有默克尔细胞的触摸穹顶传入的记录表明，默克尔细胞对动态刺激产生高频反应，并使持续放电成为可能。这些数据首次直接证明了表皮细胞和感觉神经元之间的功能性、兴奋性联系。总之，这些发现表明，默克尔细胞主动调整机械感觉反应，以促进高时空敏锐度。此外，我们的结果显示了默克尔细胞-轴突复合体的分工：默克尔细胞发出静态刺激信号，如压力，而感官传入传递动态刺激，如移动格栅。因此，默克尔细胞轴突复合体是一种独特的感觉结构，有两种感受器细胞类型，专门用于区分触摸的不同元素。
Touch submodalities, such as flutter and pressure, are mediated by somatosensory afferents whose terminal specializations extract tactile features and encode them as action potential trains with unique activity patterns. Whether non-neuronal cells tune touch receptors through active or passive mechanisms is debated. Terminal specializations are thought to function as passive mechanical filters analogous to the cochlea’s basilar membrane, which deconstructs complex sounds into tones that are transduced by mechanosensory hair cells. The model that cutaneous specializations are merely passive has been recently challenged because epidermal cells express sensory ion channels and neurotransmitters; however, direct evidence that epidermal cells excite tactile afferents is lacking. Epidermal Merkel cells display features of sensory receptor cells and make “synapse-like” contacts with slowly adapting type I (SAI) afferents. These complexes, which encode spatial features such as edges and texture, localize to skin regions with high tactile acuity, including whisker follicles, fingertips and touch domes. Here, we show that Merkel cells actively participate in touch reception in mice. First, Merkel cells display fast, touch-evoked mechanotransduction currents. Second, optogenetic approaches in intact skin show that Merkel cells are both necessary and sufficient for sustained action-potential firing in tactile afferents. Third, recordings from touch-dome afferents lacking Merkel cells demonstrate that Merkel cells confer high-frequency responses to dynamic stimuli and enable sustained firing. These data are the first to directly demonstrate a functional, excitatory connection between epidermal cells and sensory neurons. Together, these findings indicate that Merkel cells actively tune mechanosensory responses to facilitate high spatio-temporal acuity. Moreover, our results suggest a division of labour in the Merkel cell-neurite complex: Merkel cells signal static stimuli, such as pressure, whereas sensory afferents transduce dynamic stimuli, such as moving gratings. Thus, the Merkel-cell neurite complex is unique sensory structure with two receptor cell types specialized for distinct elements of discriminative touch.
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影响因子：
3.7
作者：
Haeberle H;Bryan LA;Vadakkan TJ;Dickinson ME;Lumpkin EA
通讯作者：
Lumpkin EA
影响因子：
25
作者：
通讯作者：
--
影响因子：
2.5
作者：
Koltzenburg, M;Stucky, CL;Lewin, GR
通讯作者：
Lewin, GR
影响因子：
25
作者：
Boyden, ES;Zhang, F;Deisseroth, K
通讯作者：
Deisseroth, K
DOI：
10.1126/science.1172890
发表时间：
2009-06-19
期刊：
Science (New York, N.Y.)
影响因子：
--
作者：
Maricich SM;Wellnitz SA;Nelson AM;Lesniak DR;Gerling GJ;Lumpkin EA;Zoghbi HY
通讯作者：
Zoghbi HY