 title="" class="an ">&ensp;</span>family <span  title="" class="an ">&ensp;</span>generate <span  title="" class="an ">&ensp;</span>hyperpolarization <span  title="" class="an ">&ensp;</span>activated <span  title="" class="an ">&ensp;</span>cation <span  title="" class="an ">&ensp;</span>currents <span  title="" class="an ">&ensp;</span>Ih <span  title="" class="an ">&ensp;</span>that <span  title="" class="an ">&ensp;</span>are <span  title="" class="an ">&ensp;</span>directly <span  title="" class="an "