Effects of the medial or basolateral amygdala upon social anxiety and social recognition in mice

Aim: Though social anxiety and social recognition have been studied extensively, the roles of the medial or basolateral amygdala in the control of social anxiety and social recognition remain to be determined. This study investigated the effects of excitotoxic bilateral medial or basolateral amygdala lesions upon social anxiety and social recognition in mice. Materials and methods: Animals at 9 weeks of age were given bilateral medial or basolateral amygdala lesions via infusion of N-methyl- D-aspartate and then were used for behavioral tests: anxiety-related tests (including open-field test, light-dark test, and elevated-plus maze test), social behavior test in a novel environment, social recognition test, and flavor recognition test. Results: Medial or basolateral amygdala-lesioned mice showed lower levels of anxiety and increased social behaviors in a novel environment. Destruction of the medial or basolateral amygdala neurons impaired social recognition but not flavor recognition. Conclusion: The medial or basolateral amygdala is involved in the control of anxiety-related behavior (social anxiety and social behaviors) in mice. Moreover, both the medial and the basolateral amygdala are essential for social recognition but not flavor recognition in mice.