 class="an ">&ensp;</span>P <span  title="" class="an ">&ensp;</span>Y <span  title="" class="an ">&ensp;</span>ligand <span  title="" class="an ">&ensp;</span><span  title="CAP" class="an CAP">UTP</span><span  title="" class="an ">&ensp;</span>activated <span  title="" class="an ">&ensp;</span>sustained <span  title="" class="an ">&ensp;</span>action <span  title="" class="an ">&ensp;</span>potential <span  title="" class="an ">&ensp;</span><span  title="Electrophysiology" class="an Electrophysiology">firi