Figure 5. FMRP effects on BKαβ 4... | Rockefeller University Press

Figure 5.

FMRP effects on BKαβ4 channels.(A) Representative current recordings from BKαβ4 channels in the absence (black traces) and presence of FMRP (green traces) in 0 µM and 1 µM Ca2+ after applying a family of voltage steps from −100 to +100 mV in 20-mV increments (inset below). (B–D) Average G-V relationships (B), V1/2 versus Ca2+ concentration plots (C), and mean τ-V relationships (D) in the absence (white triangles) and in the presence of FMRP (green triangles). (E) Typical records of single-channel currents from patches expressing BKαβ4 (left) and BKαβ4+FMRP channels (right) held at −40, −80, and −120 mV in the absence of Ca2+. The BKαβ4 and BKαβ4+FMRP patches contained ∼210 channels and 195 channels, respectively. (F and G) Mean PO-V (F) and Qa-V (G) relationships for BKαβ4 channels in the absence (white triangles) and in the presence (green triangles) of FMRP. Solid curves in F and G represent fits to the data using Eq.3 and Eq. 7, respectively, to yield the basic set values shown. For reference, values corresponding to BKα (±FMRP) channels (Fig. 4) are represented as dotted lines. *, P < 0.05; **, P < 0.01. Error bars represent SEM.

FMRP effects on BKαβ₄ channels. (A) Representative current recordings from BKαβ₄ channels in the absence (black traces) and presence of FMRP (green traces) in 0 µM and 1 µM Ca²⁺ after applying a family of voltage steps from −100 to +100 mV in 20-mV increments (inset below). (B–D) Average G-V relationships (B), V_1/2 versus Ca²⁺ concentration plots (C), and mean τ-V relationships (D) in the absence (white triangles) and in the presence of FMRP (green triangles). (E) Typical records of single-channel currents from patches expressing BKαβ₄ (left) and BKαβ₄+FMRP channels (right) held at −40, −80, and −120 mV in the absence of Ca²⁺. The BKαβ₄ and BKαβ₄+FMRP patches contained ∼210 channels and 195 channels, respectively. (F and G) Mean P_O-V (F) and Q_a-V (G) relationships for BKαβ₄ channels in the absence (white triangles) and in the presence (green triangles) of FMRP. Solid curves in F and G represent fits to the data using Eq.3 and Eq. 7, respectively, to yield the basic set values shown. For reference, values corresponding to BKα (±FMRP) channels (Fig. 4) are represented as dotted lines. *, P < 0.05; **, P < 0.01. Error bars represent SEM.