Figure 8.
![Figure 8. The simulated effect of genetic modification of the If. (A) Simulated effects of ablation (0.25×) and overexpression (2×) of If. The near-SL and near-SR cytosolic [Ca2+] and APs are shown during spontaneous activity, which is followed by an application of SR Ca2+ flux block and 1-Hz electrical excitation. (B) Relative changes in [Na+]i and spontaneous beating frequency by altered If expression. Insert shows the INCX with different If expression levels (0.25×, 1×, and 2×). (C) 3-D plot of the effect of varying If current density on the excitability and AP amplitude at different resting potentials.](https://cdn.rupress.org/rup/content_public/journal/jgp/132/4/10.1085_jgp.200809961/7/jgp_200809961_rgb_fig8.jpeg?Expires=1767730307&Signature=WqklPldqvkH6n64Eah371JHp7F4jYfakmtlB5wCpwFAbsfIcO9t1jwfLp8RyXaTA7-Z-AV5NOCuEVIY3s8ePOJ~uw52X3rWDa8QbhtgneDXyOeSfYwcL9PBt~t1Kw5FNQl-y5zRk6uIb1--AYmTaTJDiuKZQdylWeOhZ2k1RtVjSoN4gafeafzhe6~G1aLjpsqFjc~8KIiK9YC54PIrhaN31CalEJo7lGwOH69bmLxTBF-PLWvsbX7h5RI62yvG-1qO4uI6Uv8T4yc6aYoPAAbnIbjI04x62KDOozH9z7aTd3u2ZaWl--w8ATiDsMubOOz0Dc5YP542rD74Z9zP5EQ__&Key-Pair-Id=APKAIE5G5CRDK6RD3PGA)
The simulated effect of genetic modification of the If. (A) Simulated effects of ablation (0.25×) and overexpression (2×) of If. The near-SL and near-SR cytosolic [Ca2+] and APs are shown during spontaneous activity, which is followed by an application of SR Ca2+ flux block and 1-Hz electrical excitation. (B) Relative changes in [Na+]i and spontaneous beating frequency by altered If expression. Insert shows the INCX with different If expression levels (0.25×, 1×, and 2×). (C) 3-D plot of the effect of varying If current density on the excitability and AP amplitude at different resting potentials.
