Thermal Transduction in Somatosensory Neurons

这个项目的主要目标是研究三叉神经节中接收面部信息的神经细胞发出热刺激信号的膜机制。一种新型的微型热刺激器正在开发中，它将对这些在细胞培养环境中维持的三叉神经感觉神经元施加高度局部化和良好控制的热刺激。这种新仪器是基于一种商业上可用的微型温度计，该温度计利用光纤探头尖端的磷光体涂层发出的荧光衰减速率随温度的变化而变化。温度探头的尖端通过在黑体上覆盖一层金来起到散热器的作用。一种新的光学组件将光纤连接到氙气闪光灯和红外激光二极管。向光纤中注入红外线和蓝色辐射将使其能够同时加热探头正面并测量其表面温度。通过利用反馈回路中的温度信号和对红外激光二极管的输出进行脉冲调制，可以精确地控制高度局域化的热刺激。这种新仪器在生物学研究中应该有许多重要的应用。

The major goal of this project is to study the membrane mechanisms involved in signalling thermal stimuli by nerve cells in the trigeminal ganglion which receives information from the face. A novel, miniature thermal stimulator is being developed which will apply highly localized and well-controlled heat stimuli to these trigeminal sensory neurons which are maintained in a cell-culture environment. This new instrument is based upon a commercially available miniature thermometer which utilizes a temperature-dependent change in the rate of decay of fluorescence emitted by a phosphor coating at the tip of a fiberoptic probe. The tip of the temperature probe functions as a black-body radiator by covering it with a layer of gold. A new optical assembly couples the optical fiber to both a xenon flash light and an infrared laser diode. Injection of both infrared and blue radiation into the optic fiber will make it possible to simultaneously heat the front of the probe and measure its surface temperature. By utilizing the temperature signal in a feedback loop and pulse-modulating the output of the infrared laser diode, it is possible to accurately control the highly localized heat stimuli. This new instrument should have many important applications in biological research.