For example, Nrg1 heterozygous knockout mice with TMc-domain truncation of exon 11 were first reported in 2002 (Stefansson et al., 2002) and this original TMc-Nrg1+/− mutant strain has been reported to exhibit behavioral deficits in locomotor activity, explorative behavior, and anxiety-like behaviors (O'Tuathaigh et al., 2006; Boucher et al., 2007). This evidence concerns the gene NRG1 and Anxiety.