Individual typological characteristics of rat's behavior in open-field and passive avoidance learning

The aim of this study was to compare the learning performance of Wistar rats in passive avoidance box and open field behavior. Animals were placed in the center of the open field and their behavior was manually recorded for 5 min. Two latency periods, first motion, and exit to the center, the number of inner and outer squares crossed, grooming activity, the number of rearing in the center of the open field. Animals with short latency period of motion (4.8±0.3sec) and high ambulatory activity (113±4) were classified as group 1(hyperactive), and ones with long latency to center (7.7± 0.5 sec) that crossed less (65.5±3.9) The square were selected as group 2 (hypoactive). Then animals were placed in passive avoidance box and received 2.5 mA electric foot shock for 5 sec. After 24 h animals were tested for 3min and the latency period and the total time spent on the platform was recorded. The data showed that the good learner rats exhibited a higher number of reactions in the open field test. Since in the passive avoidance experiments the environmental influences on rats were identical, so the differences observed among rats in learning performances might be due to internal state. In conclusion this study provides evidence that learning performance is different in rats with different behavioral responses in the open field.