Serotonin Mediates Cross-Modal Reorganization of Cortical Circuits

• DOI: 10.1016/j.neuron.2011.01.016
• Publication Date: 2011-02-24T14:18:35Z
• Authors: Susumu Jitsuki; Kiwamu Takemoto; Taisuke Kawasaki; Hirobumi Tada; Aoi Takahashi; Carine Becamel; Akane Sano; Michisuke Yuzaki; R. Suzanne Zukin; Edward B. Ziff; Helmut W. Kessels; Takuya Takahashi
• Keywords: Cerebral Cortex; Male; Neurons; 0301 basic medicine; Brain Mapping; Neuronal Plasticity; Neuroscience(all); Dopamine; Amphetamines; Green Fluorescent Proteins; Long-Term Potentiation; Action Potentials; Models, Biological; Functional Laterality; Rats; Animals, Genetically Modified; 03 medical and health sciences; Animals, Newborn; Animals; Ketanserin; Nerve Net; Phosphorylation; Extracellular Signal-Regulated MAP Kinases

Loss of one type of sensory input can cause improved functionality of other sensory systems. Whereas this form of plasticity, cross-modal plasticity, is well established, the molecular and cellular mechanisms underlying it are still unclear. Here, we show that visual deprivation (VD) increases extracellular serotonin in the juvenile rat barrel cortex. This increase in serotonin levels facilitates synaptic strengthening at layer 4 to layer 2/3 synapses within the barrel cortex. Upon VD, whisker experience leads to trafficking of the AMPA-type glutamate receptors (AMPARs) into these synapses through the activation of ERK and increased phosphorylation of AMPAR subunit GluR1 at the juvenile age when natural whisker experience no longer induces synaptic GluR1 delivery. VD thereby leads to sharpening of the functional whisker-barrel map at layer 2/3. Thus, sensory deprivation of one modality leads to serotonin release in remaining modalities, facilitates GluR1-dependent synaptic strengthening, and refines cortical organization.