AKT1 and atypical Rett syndrome: In mouse models of genetic disorders that result in dendritic abnormalities such as Rett syndrome, a decrease in the soma size of hippocampal neurons was observed (Rangasamy et al., 2016), while loss of function mutations in the tuberous sclerosis complex (TSC), a negative regulator of the mTOR/Akt pathway, increase the soma size of hippocampal pyramidal neurons but decrease the density of dendritic spines causing alterations in glutamatergic transmission (Tavazoie et al., 2005).