Spatial learning of the DAT-HET rat line in an eight-arm radial maze

We conducted a study of the behavior of DAT-HET rats, which are heterozygous carriers of the knockout gene SLC6A3, encoding the dopamine transporter, in the “Eight-arm radial maze” setup. This device is a platform with branches, or “sleeves”, extending from it. The maze is designed to assess the spatial memory of rodents, in particular rats. The present study assessed the ability of animals of the above strain to remember sleeves that have food reinforcement in the first phase of the test, and to avoid them in the second phase, when there is no food reinforcement there. The expected behavior is to explore new arms. Entering a previously visited branch during the second phase of the experiment is an “error.” We analyzed a number of parameters. First of all, this is a “memory score”, which is based on counting “erroneous” inputs. In addition to the memory score, the total number of entries into the arms of the maze was calculated, as well as the number of repeated entries into the arms during a particular phase of the experiment. According to the results, DAT-HET rats did not tend to increase memory scores over a twelve-day period, unlike the control group. We also assessed the motor activity of DAT-HET rats, expressed in a greater number of entries into the arms, as increased. Analysis of the data suggests that at a certain stage of the experiment, the rats of the experimental group were characterized by an increased number of repeated entries into the arms, however, there is a large scatter of values for this characteristic.