title: A whole-brain atlas of inputs to serotonergic neurons of the dorsal and median raphe nuclei.
abstract: The serotonin system is proposed to regulate physiology and behavior and to underlie mood disorders; nevertheless, the circuitry controlling serotonergic neurons remains uncharacterized. We therefore generated a comprehensive whole-brain atlas defining the monosynaptic inputs onto forebrain-projecting serotonergic neurons of dorsal versus median raphe based on a genetically restricted transsynaptic retrograde tracing strategy. We identified discrete inputs onto serotonergic neurons from forebrain and brainstem neurons, with specific inputs from hypothalamus, cortex, basal ganglia, and midbrain, displaying a greater than anticipated complexity and diversity in cell-type-specific connectivity. We identified and functionally confirmed monosynaptic glutamatergic inputs from prefrontal cortex and lateral habenula onto serotonergic neurons as well as a direct GABAergic input from striatal projection neurons. In summary, our findings emphasize the role of hyperdirect inputs to serotonergic neurons. Cell-type-specific classification of connectivity patterns will allow for further functional analysis of the diverse but specific inputs that control serotonergic neurons during behavior.
authors.affiliation: Department of Neuroscience, Karolinska Institutet, 17177 Stockholm, Sweden.
authors.forename: Iskra
authors.initials: I
authors.lastname: Pollak Dorocic
authors.affiliation: Department of Neuroscience, Karolinska Institutet, 17177 Stockholm, Sweden.
authors.forename: Daniel
authors.initials: D
authors.lastname: Fürth
authors.affiliation: Department of Neuroscience, Karolinska Institutet, 17177 Stockholm, Sweden.
authors.forename: Yang
authors.initials: Y
authors.lastname: Xuan
authors.affiliation: Department of Neuroscience, Karolinska Institutet, 17177 Stockholm, Sweden.
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Johansson
authors.affiliation: Department of Neuroscience, Karolinska Institutet, 17177 Stockholm, Sweden.
authors.forename: Laura
authors.initials: L
authors.lastname: Pozzi
authors.affiliation: Department of Neuroscience, Karolinska Institutet, 17177 Stockholm, Sweden.
authors.forename: Gilad
authors.initials: G
authors.lastname: Silberberg
authors.affiliation: Department of Neuroscience, Karolinska Institutet, 17177 Stockholm, Sweden.
authors.forename: Marie
authors.initials: M
authors.lastname: Carlén
authors.affiliation: Department of Neuroscience, Karolinska Institutet, 17177 Stockholm, Sweden. Electronic address: dinos.meletis@ki.se.
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Meletis
mesh_terms: D000818:Animals; D001931:Brain Mapping; D023902:Chromosome Pairing / Q000502:physiology; D065847:Dorsal Raphe Nucleus / Q000378:metabolism*; D051379:Mice; D009417:Nerve Tissue / Q000378:metabolism; D009434:Neural Pathways / Q000378:metabolism; D059326:Serotonergic Neurons / Q000166:cytology* / Q000378:metabolism; D012701:Serotonin / Q000378:metabolism*
chemical_list: D012701:Serotonin