Development of hexagonal maze procedure for evaluating memory in rat.

Memory is known as a series of behavioral changes caused by an experience, while learning is a process for acquiring memory. In the present study, we suggested a new method (hexagonal maze) to evaluate the learning and memory of rats. For preliminary validation, the authors used the maze to carry out two classical experiments. At first, the performance of rats of various ages was observed in the maze. Additionally, after establishing the rapid eye movement (REM) sleep deprivation model using the modified multiple platform method (MMPM), the authors also utilized a new experimental device to analyze learning and memory responses to REM sleep deprivation in rats. Behavior of the rats in the maze was recorded by a video recorder and was then quantified. According to the behavioral characteristics, rats of various ages showed differences in memory. Middle-aged male rats exhibited a higher level compared to the young (P<0.05) and the old group (P<0.01). The results also indicated that the ability of learning and memory showed a significant decrease (P<0.05) after REM sleep deprivation. These findings were consistent with those of several similar studies using one of the adopted procedures (Morris water maze, radial arm maze and the Y-maze). Based on the above-mentioned preliminary experiments, the introduction of a hexagonal maze may provide an applicable method for analyzing learning and memory of rat.