ession <span  title="" class="an ">&ensp;</span>of <span  title="" class="an ">&ensp;</span><span  title="CAP" class="an CAP">HCN</span><span  title="" class="an ">&ensp;</span>and <span  title="" class="an ">&ensp;</span><span  title="CAP" class="an CAP">HCN</span><span  title="" class="an ">&ensp;</span>yields <span  title="" class="an ">&ensp;</span>Ih <span  title="" class="an ">&ensp;</span>currents <span  title="" class="an ">&ensp;</span>that <span  title="" class="an ">&ensp;</span>activate <span  t