2.4 UV photoactivation
The recording chamber of the Port-a-Patch was customized to accommodate a 400 µm diameter quartz optic fiber, which was placed 3–4 mm (or 5-7 mm in a subset of experiments) above the recorded cell. The original perfusion manifold was replaced by a custom manifold positioned to the side of the recording chamber opposite to the waste removal. Solution exchange was complete within 1–2 s. UV light pulses were delivered by a 310 nm fiber-coupled Mightex FCS-0310-000 LED (Mightex, Pleasanton, CA), with 40 µW intensity. Pulses were triggered by the PatchMaster software.