>photoreceptors <span  title="" class="an ">&ensp;</span>are <span  title="" class="an ">&ensp;</span>poorly <span  title="" class="an ">&ensp;</span>understood <span  title="" class="an ">&ensp;</span>I <span  title="" class="an ">&ensp;</span>have <span  title="" class="an ">&ensp;</span>investigated <span  title="" class="an ">&ensp;</span>the <span  title="" class="an ">&ensp;</span>compartmentalization <span  title="" class="an ">&ensp;</span>of <span  title="" class="an ">&ensp;</span>voltage <span  t