A four-headed planarian was produced by isolating wound cells from gap
junction-mediated communication with remaining tissues.  Green signal is
anti-synapsin staining that reveals brain and nerve cords and
anti-arrestin staining that reveals the eye spots. Yellow signal indicates
phosphorylated histone 3-positive mitotic cells (neoblasts). Red tissue is
pseudocolored bright-field DIC image of the whole worm body. Photo
courtesy of Junji Morokum and Nestor J. Oviedo. For more information, please see Tseng A and Levin M. Cracking the bioelectric code: Probing endogenous ionic controls of pattern formation. Commun Integr Biol. 2013; 6: e22595