In addition, prefrontal cortical miRNA expression levels have been reported to be altered in other psychiatric disorders: for instance, let-7d was shown to be up-regulated in the PFC of spontaneous hyperactive rats, an animal model for attention deficit hyperactivity disorder (ADHD) (35), and miR-195 was demonstrated to fine-tune regional levels of brain derived neurotrophic factor (BDNF) in the PFC of schizophrenic patients (36). This evidence concerns the gene BDNF and attention deficit-hyperactivity disorder.