Modelagem estocástica do labirinto em cruz elevado

Abstract

The elevated plus maze is widely used in studies related to anxiety in rats. The most widely used measures are the amount of entries and time spent on open arms. Recent studies analyze the movement inside the arms, but do not propose an index that summarizes the analyzes. This thesis summarizes by indices the information in one of these studies. An index uses the rst visit average time to each position of the maze and another is based on the stationary probability distribution, the rst one are able to dierentiate groups of rats submitted to dierent anxiolytic drugs. These thesis also proposes a Markov process model that incorporates more information than the other model. The comparison between the models showed overor underestimated values in the rst. Finally, this thesis proposes a Markov chains model considering the following behaviors as states: rearing, stretching, dipping, freezing and grooming. This new approach, though oversimplify the model was able to reproduce several known features of exploitation.