TY - JOUR T1 - Perturbation of Serotonin Homeostasis during Adulthood Affects Serotonergic Neuronal Circuitry JF - eneuro JO - eNeuro DO - 10.1523/ENEURO.0376-16.2017 VL - 4 IS - 2 SP - ENEURO.0376-16.2017 AU - Pratelli, Marta AU - Migliarini, Sara AU - Pelosi, Barbara AU - Napolitano, Francesco AU - Usiello, Alessandro AU - Pasqualetti, Massimo Y1 - 2017/03/01 UR - http://eneuro.org/content/4/2/ENEURO.0376-16.2017.abstract N2 - Growing evidence shows that the neurotransmitter serotonin (5-HT) modulates the fine-tuning of neuron development and the establishment of wiring patterns in the brain. However, whether serotonin is involved in the maintenance of neuronal circuitry in the adult brain remains elusive. Here, we use a Tph2fl°x conditional knockout (cKO) mouse line to assess the impact of serotonin depletion during adulthood on serotonergic system organization. Data show that the density of serotonergic fibers is increased in the hippocampus and decreased in the thalamic paraventricular nucleus (PVN) as a consequence of brain serotonin depletion. Strikingly, these defects are rescued following reestablishment of brain 5-HT signaling via administration of the serotonin precursor 5-hydroxytryptophan (5-HTP). Finally, 3D reconstruction of serotonergic fibers reveals that changes in serotonin homeostasis affect axonal branching complexity. These data demonstrate that maintaining proper serotonin homeostasis in the adult brain is crucial to preserve the correct serotonergic axonal wiring. ER -