TENM4 and bipolar disorder: However, as proper synaptic function is impaired in many neuropsychiatric disorders (Guilmatre et al., 2014) and human Teneurin-4 is associated with increased susceptibility to bipolar disorder (Psychiatric GWAS Consortium Bipolar Disorder Working Group, 2011), understanding how the Teneurins regulate central synapses is a question with clinical relevance.