cLTP and cLTD protocols

To induce chemical LTP, DIV17 neurons were washed in Mg²⁺ free buffer (in mM: NaCl 150, CaCl₂ 2, KCl 5, HEPES 10, glucose 30, strychnine 0.001, bicuculline 0.02) 3 times, and incubated in glycine buffer (Mg²⁺ free buffer with 0.2 mM glycine) at 37°C for 15 min. Then, Mg²⁺ buffer (Mg²⁺ free buffer with 2 mM MgCl₂) was added to block NMDARs and cells were incubated at 37°C for 30 min before live surface labeling with anti-RFP.

To induce chemical LTD, 14 DIV neurons were washed in Mg²⁺ free buffer 3 times, and incubated in NMDA buffer (Mg²⁺ free buffer with 0.02 mM NMDA) at 37°C for 5 min. Then, Mg²⁺ buffer was added and cells were incubated at 37°C for 1 hr before live surface labeling.