title: Parallel pathways from whisker and visual sensory cortices to distinct frontal regions of mouse neocortex.
abstract: The spatial organization of mouse frontal cortex is poorly understood. Here, we used voltage-sensitive dye to image electrical activity in the dorsal cortex of awake head-restrained mice. Whisker-deflection evoked the earliest sensory response in a localized region of primary somatosensory cortex and visual stimulation evoked the earliest responses in a localized region of primary visual cortex. Over the next milliseconds, the initial sensory response spread within the respective primary sensory cortex and into the surrounding higher order sensory cortices. In addition, secondary hotspots in the frontal cortex were evoked by whisker and visual stimulation, with the frontal hotspot for whisker deflection being more anterior and lateral compared to the frontal hotspot evoked by visual stimulation. Investigating axonal projections, we found that the somatosensory whisker cortex and the visual cortex directly innervated frontal cortex, with visual cortex axons innervating a region medial and posterior to the innervation from somatosensory cortex, consistent with the location of sensory responses in frontal cortex. In turn, the axonal outputs of these two frontal cortical areas innervate distinct regions of striatum, superior colliculus, and brainstem. Sensory input, therefore, appears to map onto modality-specific regions of frontal cortex, perhaps participating in distinct sensorimotor transformations, and directing distinct motor outputs.
authors.affiliation: École Polytechnique Fédérale de Lausanne (EPFL) , Faculty of Life Sciences, Brain Mind Institute, Laboratory of Sensory Processing, CH-1015 Lausanne, Switzerland.
authors.forename: Varun
authors.initials: V
authors.lastname: Sreenivasan
authors.affiliation: École Polytechnique Fédérale de Lausanne (EPFL) , Faculty of Life Sciences, Brain Mind Institute, Laboratory of Sensory Processing, CH-1015 Lausanne, Switzerland.
authors.forename: Alexandros
authors.initials: A
authors.lastname: Kyriakatos
authors.affiliation: École Polytechnique Fédérale de Lausanne (EPFL) , Faculty of Life Sciences, Brain Mind Institute, Laboratory of Sensory Processing, CH-1015 Lausanne, Switzerland.
authors.forename: Celine
authors.initials: C
authors.lastname: Mateo
authors.affiliation: Emory University , Department of Biology, Atlanta, Georgia 30322, United States.
authors.forename: Dieter
authors.initials: D
authors.lastname: Jaeger
authors.affiliation: École Polytechnique Fédérale de Lausanne (EPFL) , Faculty of Life Sciences, Brain Mind Institute, Laboratory of Sensory Processing, CH-1015 Lausanne, Switzerland.
authors.forename: Carl C H
authors.initials: CC
authors.lastname: Petersen
keywords: adeno-associated viral tracing of axons; mouse; sensorimotor processing; visual processing; voltage-sensitive dye imaging; whisker sensation