title: Dual-channel circuit mapping reveals sensorimotor convergence in the primary motor cortex.
abstract: Cortical cells integrate synaptic input from multiple sources, but how these different inputs are distributed across individual neurons is largely unknown. Differences in input might account for diverse responses in neighboring neurons during behavior. We present a strategy for comparing the strengths of multiple types of input onto the same neuron. We developed methods for independent dual-channel photostimulation of synaptic inputs using ChR2 together with ReaChR, a red-shifted channelrhodopsin. We used dual-channel photostimulation to probe convergence of sensory information in the mouse primary motor cortex. Input from somatosensory cortex and thalamus converges in individual neurons. Similarly, inputs from distinct somatotopic regions of the somatosensory cortex are integrated at the level of single motor cortex neurons. We next developed a ReaChR transgenic mouse under the control of both Flp- and Cre-recombinases that is an effective tool for circuit mapping. Our approach to dual-channel photostimulation enables quantitative comparison of the strengths of multiple pathways across all length scales of the brain.
authors.affiliation: Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia 20147, University of Pittsburgh School of Medicine, Department of Neurobiology, Pittsburgh, Pennsylvania 15213, hooksm@janelia.hhmi.org svobodak@janelia.hhmi.org.
authors.forename: Bryan M
authors.initials: BM
authors.lastname: Hooks
authors.affiliation: Department of Pharmacology, University of California San Diego, San Diego, California 92093, and University of Tasmania School of Medicine, Hobart, Tasmania 7000, Australia.
authors.forename: John Y
authors.identifier: http://orcid.org/0000-0002-1723-4597
authors.initials: JY
authors.lastname: Lin
authors.affiliation: Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia 20147.
authors.forename: Caiying
authors.initials: C
authors.lastname: Guo
authors.affiliation: Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia 20147, hooksm@janelia.hhmi.org svobodak@janelia.hhmi.org.
authors.forename: Karel
authors.initials: K
authors.lastname: Svoboda
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001931:Brain Mapping; D000075402:Channelrhodopsins; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects / Q000502:physiology; D005260:Female; D066298:In Vitro Techniques; D008027:Light; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D008297:Male; D051379:Mice; D009044:Motor Cortex / Q000166:cytology*; D009415:Nerve Net / Q000502:physiology*; D009474:Neurons / Q000502:physiology*; D010879:Piperazines / Q000494:pharmacology; D011810:Quinoxalines / Q000494:pharmacology; D026941:Sodium Channel Blockers / Q000494:pharmacology; D013003:Somatosensory Cortex / Q000502:physiology*; D013779:Tetrodotoxin / Q000494:pharmacology; D014161:Transduction, Genetic
chemical_list: D000075402:Channelrhodopsins; D018691:Excitatory Amino Acid Antagonists; D008164:Luminescent Proteins; D010879:Piperazines; D011810:Quinoxalines; D026941:Sodium Channel Blockers; C062865:2,3-dioxo-6-nitro-7-sulfamoylbenzo(f)quinoxaline; D013779:Tetrodotoxin; C050592:3-(2-carboxypiperazin-4-yl)propyl-1-phosphonic acid
keywords: ReaChR; circuit mapping; dual-channel stimulation; motor cortex; optogenetics; somatosensory cortex