1. ¹Mood and Anxiety Disorders Program (MAP), NIMH, National Institutes of Health, Bethesda, MD, USA
2. ²Section on Neural Development & Plasticity, NICHD, National Institutes of Health, Bethesda, MD, USA

Correspondence: Dr B Lu, Building 35, Rm 1C1004, 35 Convent Dr, MSC 3714, Bethesda, MD 20892-3714, USA. Tel: +1 301 435 2970; Fax: +1 301 496 1777; E-mail: bailu@mail.nih.gov

Received 11 July 2007; Revised 8 August 2007; Accepted 8 August 2007; Published online 19 September 2007.

Abstract

Brain-derived neurotrophic factor (BDNF) and serotonin (5-hydroxytryptamine, 5-HT) are two seemingly distinct signaling systems that play regulatory roles in many neuronal functions including survival, neurogenesis, and synaptic plasticity. A common feature of the two systems is their ability to regulate the development and plasticity of neural circuits involved in mood disorders such as depression and anxiety. BDNF promotes the survival and differentiation of 5-HT neurons. Conversely, administration of antidepressant selective serotonin reuptake inhibitors (SSRIs) enhances BDNF gene expression. There is also evidence for synergism between the two systems in affective behaviors and genetic epitasis between BDNF and the serotonin transporter genes.