n ">&ensp;</span>the <span  title="" class="an ">&ensp;</span>mutants <span  title="" class="an ">&ensp;</span>might <span  title="" class="an ">&ensp;</span>underlie <span  title="" class="an ">&ensp;</span>the <span  title="" class="an ">&ensp;</span>behavioral <span  title="" class="an ">&ensp;</span>deficits <span  title="" class="an ">&ensp;</span>At <span  title="" class="an ">&ensp;</span>the <span  title="" class="an ">&ensp;</span>cellular <span  title="" class="an ">&ensp;</span>level <span  title