Fig. 5: Perturbation of endogenous β-actin mRNA translation during chemical LTP in live neurons.

A Confocal images of the MBS-KI neuron showing optoMCP-FUS condensate formation. Cells were activated every 2 s. B Confocal images of localized condensate formation in the MBS-KI neuron. A subcellular region of the neuron was locally activated with blue light (Top). (Bottom) A kymograph was generated along a horizontal line crossing the center of the optoMCP-FUS condensate (drift-corrected). Cells were activated every 2 s. C Two-color fluorescence images of a fixed optoMCP-FUS expressing neuron with the MBS tagged β-actin gene. Yellow arrowheads indicate co-localization between β-actin mRNAs and optoMCP-FUS condensates. D (Left) The spine enlargement during the chemical long-term potentiation (cLTP). (Right) Time lines of cLTP perturbation experiments. E Representative images of dendrites during cLTP with and without blue light activation. Yellow arrowheads indicate enlarged dendritic spines. F The average spine volume change over time after cLTP. n = 174 (Dark), 307 (Light), 167 (WT), and 128 spines (CHX). Data are mean ± s.e.m. G Quantification of average spine size 160 min after cLTP stimulation in MBS-KI neurons. n = 174 (Dark), 307 (Light), and 128 spines (CHX). p = 3.52E-05 (Dark and CHX) and 7.61E-04 (Dark and Light). Data are mean ± s.e.m. H Quantification of average spine size 160 min after cLTP stimulation in the light activation condition. n = 307 (Light) and 167 spines (WT). p = 1.77E-04. Data are mean ± s.e.m. ****P < 0.0001 and ***P < 0.001. Scale bars, 10 μm (A–C) and 1 μm (E). Source data for panels (F–H) are provided in the Source Data file.