Automated Optical Analysis
of Rat Mazes

Andrew Beattie	Michael Chirlin	Leah Soffer

Background

Robin Kanarek and Wendy Mathes Foulds , researchers in the Psychology Department at Tufts University , are currently using rats to study the effects of exercise and diet in the management of diabetes. The rats are placed in various mazes used to study different aspects of behavior. The researchers hope to explore the behavioral complications associated with diabetes and to develop possible interventions for humans suffering from the disease . An automated data acquisition system was developed for this project to assist the researchers in the evaluation of the rodent behavior .

Rats used in the study are separated into three groups depending on the diet administered. The first group is a control group, which is placed on a standard laboratory diet. The other two groups are placed on a high fat diet and high sugar diet, respectively, to induce obesity and diabetes. The purpose of these diets is to explore differences in how diet impacts weight gain , activity level, and the onset of diabetes.

Mazes

The first maze used in the study is called the Morris water maze. This maze is used to assess the spatial memory of the rats. It consists of a four-foot diameter pool, filled with room temperature water made opaque with dry milk . The pool is divided into four quadrants (North, South, East and West) and a submerged platform is placed within one of the quadrants. The goal is for the rat to locate the platform, which it cannot see due to the opaqueness of the water. When first placed in the maze, the rat is unaware of the presence of a platform and swims around the outer rim of the pool. The rat is then placed on the platform for a minute, so it can study its surroundings and learn the location of the platform. In each subsequent trial the rats begin the maze in a different quadrant . With each additional trial, the time to reach the platform and the swimming pattern indicates the rat’s ability to remember and process cues. Memory is believed to deteriorate with the onset of diabetes, which can be assessed through the trials in this maze.