Does Brown Planaria Have the Capability to Learn through...

INTRODUCTION - The brown planaria or Dugesia tigrina is part of the class Turbellaria which includes free-living flatworms. Although in comparison to other species it could be considered to be a very simple organism, the nervous system, which is composed of a nerve net, of Dugesia tigrina is quite advanced and specialized (Miller 2007). The nervous system of the brown planaria can be divided into two simple sections: two nerve cords that run along the the two sides of the animal (which have been associated with the planaria’s ability to remember things) on the posterior side of the body and and primitive brain-like structures, or ganglion, on the anterior end of the animal (Agata 2009). The ganglion and the two nerve cords that run along either side of the planaria are connected and are all used in the process of sensing stimuli that occur in the animal’s surrounding. Running back and forth from the organism’s sides are transverse nerve cords; each of these co rds connect to the two lateral nerve cords at commissures. By observing the two nerve cords and the many transverse nerve cords, the Dugesia tigrina’s nervous system appears similar to a ladder (Miller 2007). On the anterior side of the brown planaria two eyespots, or ocelli, are found on top of the head (Agata 2009). Although these eyespots do not necessarily allow the Dugesia tigrina the capability to see pictures, as the eyes of more advanced organisms do, they are able to detect light. Brown planaria, who