Altered drug resistance of microtubules in cells exposed to infrared light pulses: Are microtubules the 'nerves' of cells?

This article describes the first quantitative assay of the response of an entire population of cultured mammalian cells to a pulsating near-infrared signal. The assay measures the change of resistance to nocodazole of reconstituted cytoplasmic asters of irradiated cells. Using this assay on CVI cells, I obtained results suggesting that pulsating near-infrared signals of 1 s pulselength reduced the stability of the radial microtubules around the centrosome. The results are consistent with the interpretation that the centrosome responded to the light by sending signals along its radial array of microtubules whose stability was then altered. The results may be an example of a more general function of the centrosome to integrate exogenous signals and send response signals along microtubules to various sites within the cell.