iMGLs express the microglial-enriched purinergic receptor P2ry12, which sense extracellular nucleotides from degenerating neurons, and is critical for microglial homeostatic function (De Simone et al., 2010; Moore et al., 2015) (Figure S2A,B). In response to ADP, iMGLs chemotax toward ADP and produce detectable calcium transients (Figure 3D,E), that were both negated by a P2ry12-specific inhibitor, PSB0739. These physiological findings further underscore that iMGLs respond appropriately to stimuli and express functional surface receptors, such as P2ry12, enabling quantitative analyses of microglial physiology.
