Here we show that induction of brain-derived neurotrophic factor (Bdnf), a critical neurotrophin involved in a wide range of neurobiological functions, is significantly diminished or absent in the hippocampus of mice lacking Egr3. Dysfunction of BDNF has been implicated in numerous neuropsychiatric disorders (Autry and Monteggia, 2012), including bipolar disorder and schizophrenia (Durany et al., 2001). The gene discussed is EGR3; the disease is bipolar disorder.