Memory improves precision of cell sensing in fluctuating environments

TL;DR

This paper demonstrates that cell memory, especially when dynamically adjusted, enhances the precision of chemical sensing in fluctuating environments, supported by analytical formulas and experimental data from chemotactic cells.

Contribution

It provides analytical formulas showing how cell memory improves sensing accuracy and reveals that dynamic memory adjustment enhances precision even in noisy conditions.

Findings

Memory significantly improves sensing in weakly fluctuating environments.

Dynamic memory adjustment enhances sensing precision in strongly fluctuating environments.

Experimental evidence from Dictyostelium discoideum supports the theoretical predictions.

Abstract

Biological cells are often found to sense their chemical environment near the single-molecule detection limit. Surprisingly, this precision is higher than simple estimates of the fundamental physical limit, hinting towards active sensing strategies. In this work, we analyse the effect of cell memory, e.g. from slow biochemical processes, on the precision of sensing by cell-surface receptors. We derive analytical formulas, which show that memory significantly improves sensing in weakly fluctuating environments. However, surprisingly when memory is adjusted dynamically, the precision is always improved, even in strongly fluctuating environments. In support of this prediction we quantify the directional biases in chemotactic Dictyostelium discoideum cells in a flow chamber with alternating chemical gradients. The strong similarities between cell sensing and control engineering suggest universal problem-solving strategies of living matter.