Department of Physics, <a href="https://ror.org/0168r3w48">University of California, San Diego</a>, La Jolla, California 92093, USA.
Phys Rev Lett. 2024 Aug 9;133(6):068401. doi: 10.1103/PhysRevLett.133.068401.
When cells of the social amoeba Dictyostelium discoideum are starved of nutrients they start to synthesize and secrete the chemical messenger and chemoattractant cyclic adenosine monophosphate (cAMP). This signal is relayed by other cells, resulting in the establishment of periodic waves. The cells aggregate through chemotaxis toward the center of these waves. We investigated the chemotactic response of individual cells to repeated exposure to waves of cAMP generated by a microfluidic device. For fast-moving waves (short period), the chemotactic ability of the cells was found to increase upon exposure to more waves, suggesting the development of a memory over several cycles. This effect was not significant for slow-moving waves (large period). We show that the experimental results are consistent with a local excitation global inhibition-based model, extended by including a component that rises and decays slowly and that is activated by the temporal gradient of cAMP concentration. The observed enhancement in chemotaxis is relevant to populations in the wild: once sustained, periodic waves of the chemoattractant are established, it is beneficial to cells to improve their chemotactic ability in order to reach the aggregation center sooner.
当粘菌细胞（社会变形虫）缺乏营养时，它们开始合成并分泌化学信使和趋化性化学引诱物环腺苷酸（cAMP）。这种信号被其他细胞传递，导致周期性波的建立。细胞通过向这些波的中心的趋化性聚集。我们研究了单个细胞对由微流控装置产生的 cAMP 波的重复暴露的趋化反应。对于快速移动的波（短周期），发现细胞的趋化能力在暴露于更多波后增加，表明在几个周期中发展出记忆。对于缓慢移动的波（大周期），这种效应并不显著。我们表明，实验结果与基于局部兴奋全局抑制的模型一致，该模型通过包括一个缓慢上升和下降且由 cAMP 浓度的时间梯度激活的组件进行扩展。观察到的趋化性增强与野生种群有关：一旦建立了持续的、周期性的趋化波，提高趋化性能力对细胞来说是有益的，以便更早地到达聚集中心。
