Learning and memory abilities between BALB/c and C57BL/6 mice after voluntary movement / 中国组织工程研究

ABSTRACT

BACKGROUND: BALB/c and C57BL/6 mice are two inbred strains, but after voluntary movement, there is no report on how to scientifical y reasonably select behavioral experiment methods and indicators and to evaluate the learning and memory abilities of mice. OBJECTIVE: To analyze and compare the behavioral indicators between BALB/c and C57BL/6 mice fol owing voluntary wheel running, to explore the effect of exercise on learning and memory, and to provide a reference for selecting reasonable behavioral indicators. METHODS: 2.5-month-old BALB/c and C57BL/6 mice were randomly divided into control and voluntary wheel running groups. Independent running wheel movement of mice was recorded with VitalView system. 4 weeks later, newborn neurons were labeled via DCX immunofluorescence. Spatial learning, memory and exploration abilities were compared through new arm test, new object recognition test and Morris water maze test. RESULTS AND CONCLUSION: (1) The mean spontaneous activity of BALB/c mice daily was 2.56 fold of that of C57BL/6 mice during wheel running (P < 0.001). (2) Hippocampal DCX-positive cel s in exercised BALB/c and C57BL/6 mice were more than those in control group. (3) Meantime, exhibited by higher frequencies to explore new arm or object, and longer time and distance of moving around them, the learning and exploring capability was improved after exercising (P < 0.001), especial y in BALB/c mice. (4) Wheel running C57BL/6 mice exhibited progressed spatial learning and memory abilities compared with control mice in Morris water maze test, characterized by decreased latency to target, elevated target crossings and longer time or distance in quadrant zone (P < 0.05). However, there was no significant difference between wheel running and control BALB/c mice. Taken these data together, voluntary wheel running contributed to hippocampal neurogenesis of BALB/c and C57BL/6 mice, accompanied by the change of learning and memory capability, which could be detected properly via both new arm test and new object recognition test, but for Morris water maze test, C57BL/6 mice might be superior to BALB/c mice.