Gradient perception

From Biology-Online Dictionary
Jump to: navigation, search

Gradient perception

(Science: cell biology) problem faced by a cell that is to respond directionally to a gradient of, for example: a diffusible attractant chemical.

in a spatial mechanism the cell would compare receptor occupancy at different sites on the cell surface, a temporal mechanism would involve comparison of concentrations at different times, the cell moving randomly between readings.

in pseudospatial sensing, the cell would detect the gradient as a consequence of positive Feedback to protrusive activity if receptor occupancy increased with time as the protrusion moved up gradient. Few cell types have been unambiguously shown to detect gradients.