BALB/c mice: low sociability and other phenotypes that may be relevant to autism.

Low sociability is one of the most prominent and disabling symptoms of autism. The biology of sociability is not well understood, and there is no available treatment that adequately improves social functioning in most autistic patients. The development of animal models of reduced sociability can aid in the elucidation of the biology of social behaviors, and may ultimately shed light on the biology of autism. This paper will review evidence that mice of the BALB/c inbred strain show relatively low levels of social interaction in various settings and across various stages of development, including male-male interactions, female-female interactions, male-female sexual interactions, and parenting behaviors. Taken together, this evidence suggests a generally low level of sociability in BALB/c mice that may be relevant to autism. BALB/c mice also show other phenotypes with possible relevance to autism, including relatively high levels of anxiety and aggressive behaviors, large brain size, underdevelopment of the corpus callosum, and low levels of brain serotonin. Further research is needed to determine the relationship among these BALB/c phenotypes, and to determine their possible relevance to autism. In conclusion, the BALB/c inbred strain may be a useful animal model for identifying genes and neurobiological pathways involved in autism-related phenotypes.