Role of spatial heterogeneity on the collective dynamics of cilia beating in a minimal 1D model

TL;DR

This study explores how spatial heterogeneity influences the collective beating of cilia using a simple 1D model, revealing bifurcations and frequency distributions that depend on cluster arrangements and density.

Contribution

It introduces a minimal 1D model to analyze the impact of spatial heterogeneity on cilia coordination, highlighting the importance of cluster distribution and density.

Findings

Phase drift and bifurcation in small systems as cluster distance varies.

Distribution of beating frequencies in large systems.

Patchy cilia arrangements show robust collective behavior.

Abstract

Cilia are elastic hairlike protuberances of the cell membrane found in various unicellular organisms and in several tissues of most living organisms. In some tissues such as the airway tissues of the lung, the coordinated beating of cilia induce a fluid flow of crucial importance as it allows the continuous cleaning of our bronchia, known as mucociliary clearance. While most of the models addressing the question of collective dynamics and metachronal wave consider homogeneous carpets of cilia, experimental observations rather show that cilia clusters are heterogeneously distributed over the tissue surface. The purpose of this paper is to investigate the role of spatial heterogeneity on the coherent beating of cilia using a very simple one dimensional model for cilia known as the rower model. We systematically study systems consisting of a few rowers to hundreds of rowers and we investigate the conditions for the emergence of collective beating. When considering a small number of rowers, a phase drift occurs, hence a bifurcation in beating frequency is observed as the distance between rowers clusters is changed. In the case of many rowers, a distribution of frequencies is observed. We found in particular the pattern of the patchy structure that shows the best robustness in collective beating behavior, as the density of cilia is varied over a wide range.