title: Increased expression of the 5-HT6 receptor by viral mediated gene transfer into posterior but not anterior dorsomedial striatum interferes with acquisition of a discrete action-outcome task.
abstract: Serotonin plays a role in reinforcement learning; however, it is not known which serotonin receptors mediate these effects. Serotonin 6 (5-HT(6)) receptors are abundant in the striatum, a brain area that is involved in reinforcement learning. We previously found that 5-HT(6) receptors in the dorsomedial striatum (DMS) affect reinforcement learning or consolidation over several days. We use viral-mediated gene transfer to discern the role that 5-HT(6) receptors play in mediating post-synaptic responses in anterior versus posterior DMS. Male Long-Evans rats were used to study learning acquisition during a single session of 100 trials on a fixed interval of 20 seconds. In a discrete action-outcome learning task, rats had 10 seconds to press a lever to induce lever retraction and sucrose pellet delivery. In another group of rats, the task had a lever that was continuously extended but only active every 20 seconds, allowing for repetitive, mostly non-reinforced, lever pressing. Results demonstrate that increased expression of 5-HT(6) receptors in the posterior DMS interferes with earning sucrose pellets in only the former task. We take this to indicate that 5-HT(6) receptor signaling in the posterior DMS interferes with acquisition of discrete action-outcome responding.
authors.affiliation: Graduate Program in Neurobiology and Behavior, Medical Scientist Training Program, Psychiatry and Behavioral Sciences, University of Washington, School of Medicine, Seattle, WA, USA.
authors.forename: Daniel
authors.initials: D
authors.lastname: Eskenazi
authors.forename: John F
authors.initials: JF
authors.lastname: Neumaier
mesh_terms: D000818:Animals; D001479:Basal Ganglia / Q000378:metabolism*; D001522:Behavior, Animal; D003216:Conditioning, Operant; D004435:Eating; D018014:Gene Transfer Techniques; D005822:Genetic Vectors; D008297:Male; D051381:Rats; D020318:Rats, Long-Evans; D011985:Receptors, Serotonin / Q000096:biosynthesis* / Q000235:genetics; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D012054:Reinforcement, Psychology; D018139:Simplexvirus / Q000235:genetics*; D013395:Sucrose / Q000008:administration & dosage; D013997:Time Factors; D015854:Up-Regulation
chemical_list: D011985:Receptors, Serotonin; D011993:Recombinant Fusion Proteins; C097216:serotonin 6 receptor; D013395:Sucrose