Detailed studies of the PTEN-related ASD mouse models have revealed several cellular structural abnormalities. Generally, neuronal cells lacking Pten have increased size, more abundant and ectopic axonal projections, increased numbers of presynaptic vesicles, increased numbers of dendritic spines, and larger postsynaptic densities (Kwon et al., 2006a; Fraser et al., 2008; Luikart et al., 2011a; Williams et al., 2015). However, one study suggests that overall numbers of dendritic spines are unchanged in neurons lacking Pten, but the spines are larger and there are a greater proportion of spines with mature morphology (Haws et al., 2014). The Ptenm3m4 mice, which have decreased nuclear Pten but normal levels of cytoplasmic Pten, have neurons with increased soma size but normal dendritic thickness (Tilot et al., 2014), indicating the importance of Pten in determining cellular morphology locally.
