THE NOISE PROBLEM IN CHEMOTAXIS

The chemotactic capability of some cells is infinitely useful for their survival. This capability is based upon mechanisms detecting concentration difference across the cell diameter. This signal (concentration gradient) decreases with the distance from the source. On the other hand, there is a noise caused by thermal motions of molecules infecting this signal. There is a threshold distance from the source beyond which the signal is weaker than noise and the cells lying there could not make a definite decision about the source direction. Probable mechanisms diminishing the noise and extending this distance threshold have been discussed in this article. It has also been argued that if the diffusion coefficient would be a function of concentration, it could cause different ways of Signal-to-Noise Ratio dependence on distance and imply interesting chemotactic behaviors of cell populations.

کلیدواژه ها:

Chemotaxis ، Signal ، Noise ، Relay ، Random walking