FIGURE 4.

Apical membrane immunofluorescence localisation and ion currents from the choroid plexus of the Kir7.1-HA mouse. (A) Cryosections of choroid plexus epithelia were probed with the rat anti-HA monoclonal antibody. Confocal images obtained from choroid plexus of heterozygous Kir7.1-HA (left) and WT littermates WT (right) (n = 5). Scale bar represents 50 μm. (B,C) Show cell-attached patch-clamp recordings obtained from apical membranes of choroid plexus of Kir7.1-HA mice. The pipette solution contained 145 mM Rb⁺ without (B) and with (C) 1 mM Ba²⁺. Bath solution had 145 mM K⁺ in both cases. (D) Steady-state current-voltage relation for currents measured in (B). (E) Current–voltage relations for experiment in (C). Currents shown were taken at the initial peak (circles) or at the end of the pulse (triangles). (F) Comparison of maximal currents at –180 mV in recordings from WT (circles and column on the left) or Kir7.1-HA mice (triangles and column on the right). Means ± SD and individual points, n = 8 and 9 respectively.