Finally, we showed that lack of Cdk5 activity in p35 knockout mice (KO) leads to permanent reduction in the final number of a subtype of interneurons (i.e., PV- and somatostatin (SST)-positive) that may affect neuronal circuit formation, thus increasing the risk of neurodevelopmental disorders, such as schizophrenia. This evidence concerns the gene SST and neurodevelopmental disorder.