膜電位の光学的検出とポテンシァル・プローブ

概要

論文の詳細を見る
Physiologists and biophysicists have long been interested in optical changes coupled with neuron or muscle activity. Although the mechanism of optical changes is not well understood, it has become clear that many of optical changes are associated with changes in membrane potential. Thus, it was suggested that these optical signals, can in principle, be used to monitor the membrane potential. This application has been made more feasible recently by the finding that certain merocyanines, cyanines, and oxonols show large signals in fluorescence and/or absorption during action potentials in squid axons. With these dyes, changes in optical properties that were linearly related to membrane potential were found. The signal-to-noise ratios in squid axons may be very large (-100:1).<BR>Quite recently, it became clear that the optical method of measuring membrane potential was a powerful tool for systems where, for reasons of scale, topology, or complexity, the use of microelectrodes would be inconvenient or impossible. Systems studied thus far include T-system and/or sarcoplasmic reticulum of muscle, invertebrate ganglion, and suspensions of cells and subcellular organelles.<BR>This article first emphsized the optical changes associated with membrane potential while optical monitoring of membrane potential was subsequently reviewed.