(Christian Madry & Josef Priller, Berlin)

The two-pore domain potassium channel THIK-1, encoded by the kcnk13 gene, is tonically active in microglia and regulates microglial ramification and tissue surveillance. THIK-1 activity is also essential for inflammasome assembly and the release of IL-1b in response to lipopolysaccharide (LPS) and ATP. In this project, we will conditionally deplete THIK-1 in microglia by crossing cx3cr1CreER-IRES-YFP/+ mice with kcnk13fl/fl mice (Priller group). We will examine the mice at 1, 2 and 4 months of age in the open field, elevated plus maze, Y-maze, novel object recognition task, forced swim test, and rotarod motor learning task. Immunohistochemical analysis of the brain and spinal cord will be performed. In addition, we will perform electrophysiological recordings of hippocampal pyramidal neurons and microglia in acute brain slices (Madry group). Patch-clamping of microglial cells in situ will be combined with real-time imaging of their surveillance activity by two-photon microscopy. Basal neuronal transmission will be examined, and compared with microglial activation by ATP and LPS. Changes of neural oscillations and synaptic plasticity will be determined.