title: A genetically specified connectomics approach applied to long-range feeding regulatory circuits.
abstract: Synaptic connectivity and molecular composition provide a blueprint for information processing in neural circuits. Detailed structural analysis of neural circuits requires nanometer resolution, which can be obtained with serial-section electron microscopy. However, this technique remains challenging for reconstructing molecularly defined synapses. We used a genetically encoded synaptic marker for electron microscopy (GESEM) based on intra-vesicular generation of electron-dense labeling in axonal boutons. This approach allowed the identification of synapses from Cre recombinase-expressing or GAL4-expressing neurons in the mouse and fly with excellent preservation of ultrastructure. We applied this tool to visualize long-range connectivity of AGRP and POMC neurons in the mouse, two molecularly defined hypothalamic populations that are important for feeding behavior. Combining selective ultrastructural reconstruction of neuropil with functional and viral circuit mapping, we characterized some basic features of circuit organization for axon projections of these cell types. Our findings demonstrate that GESEM labeling enables long-range connectomics with molecularly defined cell types.
authors.affiliation: Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia, USA.
authors.forename: Deniz
authors.initials: D
authors.lastname: Atasoy
authors.affiliation: Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia, USA.
authors.forename: J Nicholas
authors.initials: JN
authors.lastname: Betley
authors.affiliation: Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia, USA.
authors.forename: Wei-Ping
authors.initials: WP
authors.lastname: Li
authors.affiliation: Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia, USA.
authors.forename: Helen H
authors.initials: HH
authors.lastname: Su
authors.affiliation: Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia, USA.
authors.forename: Sinem M
authors.initials: SM
authors.lastname: Sertel
authors.affiliation: Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia, USA.
authors.forename: Louis K
authors.initials: LK
authors.lastname: Scheffer
authors.affiliation: Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia, USA.
authors.forename: Julie H
authors.initials: JH
authors.lastname: Simpson
authors.affiliation: Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia, USA.
authors.forename: Richard D
authors.initials: RD
authors.lastname: Fetter
authors.affiliation: Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia, USA.
authors.forename: Scott M
authors.initials: SM
authors.lastname: Sternson
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D030801:Animals, Genetically Modified; D063132:Connectome / Q000379:methods*; D004331:Drosophila melanogaster; D005247:Feeding Behavior / Q000502:physiology*; D008297:Male; D051379:Mice; D057507:Mice, 129 Strain; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D008969:Molecular Sequence Data; D009415:Nerve Net / Q000502:physiology*; D009924:Organ Culture Techniques; D010775:Photic Stimulation / Q000379:methods; D013997:Time Factors