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">UDP</span><span  title="" class="an ">&ensp;</span>never <span  title="" class="an ">&ensp;</span>activated <span  title="" class="an ">&ensp;</span>C <span  title="" class="an ">&ensp;</span>fibers <span  title="" class="an ">&ensp;</span>In <span  title="" class="an ">&ensp;</span>comparison <span  title="" class="an ">&ensp;</span>to <span  title="