Imaging solution

Modified hemolymph-like 3.1 (HL3.1) solution was prepared fresh on the day of an experiment and used both as a dissecting and imaging buffer. HL3.1 consists of 70 mm NaCl, 5 mmKCl, 1.5 mmCaCl₂, 2 mm MgCl₂, 5 mm HEPES, 115 mm sucrose, 5 mm trehalose, and pH 7.2 with NaHCO₃ (Sigma-Aldrich).

Modified hemolymph-like 3 (HL3) solution used in Extended Data Figure 3-1 consisted of 70 mm NaCl, 5 mmKCl, 1.5 mm CaCl₂, 20 mm MgCl₂, 5 mm HEPES, 115 mm sucrose, 5 mm trehalose, and pH 7.2 with NaHCO₃ (Sigma-Aldrich). Artificial CSF (aCSF) contained 25 mm HEPES, 120 mm NaCl, 5 mmKCl, 2 mm CaCl₂, 2 mm MgCl₂, and 30 mm glucose buffered to a pH of 7.4 using NaOH.