A. Representative voltage-clamp recordings of HCN1
currents (left) following incubation for 20 min in the absence or presence of 10
μM of the indicated reagent. Tail currents (right) are shown on expanded
scales. In each case the black trace is the current recorded at an activation
potential of −65 mV. To permit comparison, all recordings were obtained
on the same day from distinct oocytes from a single donor frog. Scale bars are 2
μA and 1s (left) and 200 nA and 50 ms (right).
B. Schematic representation of
2,6-di-iso-propyl phenyls. Substitutions at the 1-position (as
per the legend) describe molecules whose effects are
reported in A and C.
C. Normalized steady-state activation curves constructed
from the records shown in A. The smooth lines are fits of the
Boltzmann function. Symbols represent molecules as described in
B.