Figure 5.

The lack of connexin expression in astrocytes impacts slow oscillations in olfactory bulb slices. A, B, Typical mitral cell recordings in WT mice (A) and dKO mice for the two astroglial Cxs (Cx30 and Cx43; B). Detected UP states are highlighted by blue rectangles. Note that action potentials have been truncated for clarity. To allow comparison, cells were maintained at −60 mV by current injection. C–F, Mitral cell oscillatory properties were examined in WT and dKO mice. C, The frequency of the UP states is not affected by astroglial Cx deletion (two-tailed Mann and Whitney U test, p = 0.43; WT, n = 39; dKO, n = 38). D, E, No significant differences are detected for UP and DOWN state durations between WT and dKO MCs (two-tailed Mann and Whitney U test, p = 0.46 and 0.94, respectively). F, However, a significant reduction in the amplitude separating the DOWN from the UP state membrane potentials (defined as UP state amplitude) is observed in dKO MCs compared to WT MCs. ***p < 0.0001 (two-tailed Mann and Whitney U test). Similar results were obtained for recordings performed without current injection. G, The firing rate during UP states is reduced in dKO compared to WT MCs when cells are monitored at spontaneous membrane potential (WT, n = 45; dKO, n = 32). *p = 0.04 (one-tailed Mann and Whitney U test).