Cell Biology Division, MRC Laboratory of Molecular Biology, Hills Road, Cambridge CB2 2QH, UK.
Neuron. 2011 Apr 28;70(2):299-309. doi: 10.1016/j.neuron.2011.02.046.
The nematode C. elegans senses head and nose touch using multiple classes of mechanoreceptor neurons that are electrically coupled through a network of gap junctions. Using in vivo neuroimaging, we have found that multidendritic nociceptors in the head respond to harsh touch throughout their receptive field but respond to gentle touch only at the tip of the nose. Whereas the harsh touch response depends solely on cell-autonomous mechanosensory channels, gentle nose touch responses require facilitation by additional nose touch mechanoreceptors, which couple electrically to the nociceptors in a hub-and-spoke gap junction network. Conversely, nociceptor activity indirectly facilitates activation of the nose touch neurons, demonstrating that information flow across the network is bidirectional. Thus, a simple gap-junction circuit acts as a coincidence detector that allows primary sensory neurons to integrate information from neighboring mechanoreceptors and generate somatosensory perception.
秀丽隐杆线虫利用多类机械感受器神经元来感知头部和鼻子的触碰，这些神经元通过缝隙连接网络实现电耦合。通过体内神经影像学方法，我们发现头部的多树突伤害感受器在整个感受野内对强烈触碰有反应，但仅在鼻子的尖端对轻柔触碰有反应。强烈触碰反应仅依赖于细胞自主的机械感觉通道，而轻柔的鼻子触碰反应需要额外的鼻子触碰机械感受器的促进，这些感受器通过轮辐式缝隙连接网络与伤害感受器实现电耦合。相反，伤害感受器的活动间接促进了鼻子触碰神经元的激活，表明信息在网络中的流动是双向的。因此，一个简单的缝隙连接电路充当了一个符合检测器，允许初级感觉神经元整合来自相邻机械感受器的信息，并产生躯体感觉感知。
