Fig. 4

Upregulation of Sur1-Trpm4 channels in TLR4-activated primary rat adult microglia. a qPCR analysis of isolated cells (left) showing expression of microglial P2y12 and Tlr4, and no expression of neuronal Neun or astrocytic Gfap; data are from three independent replicates; also shown are representative immunofluorescence images of Iba1⁺ isolated microglia under control conditions (normal saline, NS) versus 24 h after TLR4 ligation by LPS (1 μg/mL). b Fold change in mRNA for Abcc8, Trpm4, and Kcnj11 in primary cultured adult microglia activated by ligation of TLR4 with LPS (1 μg/mL) for 24 h; induction of I1-1β mRNA was used as a positive control; ten replicates; * p < 0.05; ** p < 0.01. c Representative immunofluorescence images of primary cultured adult microglia showing expression of Sur1, Trpm4, and Kir6.2 protein under control (CTR) conditions and after ligation of TLR4 with LPS (1 μg/mL) for 24 h. d Whole-cell currents in quiescent primary cultured microglia recorded with physiological solutions (upper) and with Cs⁺-containing solutions (lower) during ramp pulses, shown at high (upper) and low (lower) temporal resolution; Sur1-activation by diazoxide yielded the difference current attributable to K_ATP (red). e Whole-cell currents in TLR4-activated primary cultured microglia recorded with Cs⁺-containing solutions during ramp pulses, shown at low (left) and high (right) temporal resolution, with Sur1-activation by diazoxide (100 μM), and blockade by glibenclamide (5 μM) (upper) or 9-phenanthrol (10 μM) (lower); the tracings in d and e are representative of six to eight cells per condition, with ramp pulses −100 to +100 mV in 500 ms, repeated every 15 s; holding potential, −50 mV