Nanoscopic Tracking of Glycine Receptors Using a New Chloride Sensor

A fresh approach lets scientists watch glycine receptors in action at the nanometer level. Glycine receptors, which help dampen nerve signals, have been hard to study because usual fluorescent tags interfere with their normal behaviour. The new design attaches a chloride‑sensitive dye, mClYFP, to the outside tip of the GlyRα2 protein. This fusion keeps the channel working and lets researchers see real‑time changes in chloride ions when glycine binds, using a special microscopy technique called total internal reflection fluorescence. The team ran electrical tests alongside the light‑based recordings to confirm that both parts of the new construct behave correctly. The channel still opens and closes as it should, while the external dye reports chloride shifts that match what happens inside living cells.Because the tag sits outside the cell, it can be read without penetrating the membrane, making the method less invasive. Tests in brain cells that naturally use these receptors show the sensor works well in real tissue, especially in the striatum region. This extracellular sensor allows scientists to map chloride flow across tiny receptor clusters in living neurons. By providing a clear picture of how these receptors signal at the nanoscale, the technique opens new doors for studying brain signalling and could help in understanding disorders linked to inhibitory neurotransmission.