Scoring of social interactions and play in mice during adolescence

This unit provides a description of methods that have proven useful in characterizing amicable and playful interactions of developing mice. Such a procedure can be used to evaluate the effects of perinatal and/or ongoing treatments on the social performance of periadolescent subjects of either or both sexes. It can also be complemented by the use of specific acute drug challenges, which can throw light on possible alterations of the subserving neurochemical systems. Basically, it consists of video recording brief sessions of spontaneous pair interactions and their subsequent observation and scoring according to a detailed mouse ethogram. The protocol is quite sensitive to subtle behavioral effects, which could be undetectable by other means, and it is most useful when repeated over several days to draw an ontogenetic profile. Critical parameters that must be considered when planning, e.g., sample size and timing of observations, are discussed in detail, along with the key issue of controlling for litter effects.