Energetics of active fluctuations in living cells

TL;DR

This paper proposes new experimental protocols to investigate the energetics of active fluctuations in living cells using microrheology, including thermodynamic-like cycles and response measurements, demonstrated on an active Brownian oscillator model.

Contribution

It introduces innovative experimental methods to analyze active fluctuations in cells, extending beyond traditional microrheology techniques.

Findings

Proposed protocols can reveal energetic aspects of cellular activity.

Demonstrated methods on an active Brownian oscillator model.

Potential to deepen understanding of cellular nonequilibrium processes.

Abstract

The nonequilibrium activity taking place in a living cell can be monitored with a tracer embedded in the medium. While microrheology experiments based on optical manipulation of such probes have become increasingly standard, we put forward a number of experiments with alternative protocols that, we claim, will provide new insight into the energetics of active fluctuations. These are based on either performing thermodynamic--like cycles in control-parameter space, or on determining response to external perturbations of the confining trap beyond simple translation. We illustrate our proposals on an active itinerant Brownian oscillator modeling the dynamics of a probe embedded in a living medium.