Comparisons of behavior and synaptic plasticity among three C57BL/6 substrains

The C57BL/6 is one of the most frequently used mouse strains in neuroscience. Although it is well recognized that genetic background has a critical impact on the behavior and physiology of different strains of mice, the differences among substrains of C57BL/6 are not well appreciated. Here, we compared three substrains of C57BL/6 (C57BL/6NCrljOri, C57BL/6NTacSam, and C57BL/6JBomTac) in a series of behavioral tasks examining both general behavior, and learning and memory. In addition, we have also performed electrophysiological analyses including long-term potentiation (LTP) in the hippocampus, which is considered a cellular mechanism for learning and memory. We found that there are significant differences between C57BL/6JBomTac and the other two substrains in their behavioral phenotypes, including motor coordination, anxiety, and freezing in classical fear conditioning. However, the three substrains show comparable levels of hippocampal LTP. Our findings provide guidelines for choosing the most appropriate substrain for the intended studies.