Cell‑Type‑Resolved Effects of Yellow 5 on Cortical Ca²⁺ Signaling during Laser‑Induced Shockwaves

This study examines how the artificial food dye Yellow 5 (tartrazine) alters calcium signaling in neurons and astrocytes during laser‑induced shockwave (LIS) injury. Primary mouse cortical cultures were loaded with Fluo‑4 AM and Ethidium Homodimer III to track calcium dynamics and exclude non‑viable cells. Cells were treated with 100 µM Yellow 5 prior to LIS, and calcium activity was recorded every three seconds for approximately 20 minutes. Neurons and astrocytes were distinguished by morphology, and single‑cell ΔF/F₀ traces were analyzed. LIS alone produced strong calcium spikes in both cell types. Yellow 5 significantly increased calcium amplitudes in neurons and astrocytes compared to controls. Under control conditions, astrocytes exhibited larger calcium elevations than neurons, but this difference disappeared with Yellow 5 treatment. Event duration (FWHM) was shortened in Yellow 5‑treated astrocytes but unchanged in neurons, indicating cell‑type‑specific modulation of calcium dynamics. These findings suggest that Yellow 5 reshapes mechano‑evoked calcium responses differently in neurons and glia, potentially by altering calcium buffering or signaling pathways. Future work will assess whether these changes influence cell survival or injury propagation.