As compared to wild-type monkeys, MECP2 transgenic monkeys exhibited a higher frequency of repetitive circular locomotion and increased stress responses, as measured by the threat-related anxiety and defensive test.
IGF1 levels are also reduced in older, fully symptomatic heterozygous (Mecp2(-/+)) female mice, and short-term treatment with rhIGF1 in these animals improves respiratory patterns, reduces anxiety levels, and increases exploratory behavior.