et al., 2011). However, deletion of exon 11 (Schmeisser et al., 2012) or exon 21 (Kouser et al, 2013) of Shank3 had no effect on either spine density nor on dendritic complexity in CA1 neurons. This may have been due to the age of the mice tested, as deletion of exons 4–9 of Shank3 had an age-dependent effect on spine density and morphology: CA1 neurons from 4 week old mice had decreased spine density and increased spine length, whereas CA1 neurons from 10 week old mice had normal spine density, but decreased spine length (Wang et al., 2011).
