TY - JOUR T1 - Multiple non-auditory cortical regions innervate the auditory midbrain JF - bioRxiv DO - 10.1101/627232 SP - 627232 AU - Bas MJ Olthof AU - Adrian Rees AU - Sarah E Gartside Y1 - 2019/01/01 UR - http://biorxiv.org/content/early/2019/05/03/627232.abstract N2 - In sensory perception, feedback connections from higher to lower levels in the processing hierarchy are considered to be of major importance. In the auditory system, connections from the auditory cortex to the inferior colliculus -the auditory midbrain- are well established, but the existence of inputs to the inferior colliculus from other, non-auditory,-cortical areas has not been systematically investigated. Using retrograde tracing we show that visual, somatosensory, motor, and prefrontal cortices all project extensively to the inferior colliculus. These connections are bilateral, with an ipsilateral dominance, but those from motor and prefrontal cortex show a less pronounced lateralization. Anterograde tracing reveals that cortical fibres terminate in all three subdivisions of the inferior colliculus, and target both GABAergic inhibitory, and putative glutamatergic excitatory neurons. These findings indicate that sound processing in the auditory midbrain is influenced by multiple sensory, behavioural, and executive cortical systems.ACauditory cortexAIagranular insular cortexAu1primary auditory cortexAuDsecondary auditory cortex dorsal zoneAuVsecondary auditory cortex, ventral zoneCg1cingulate cortex area 1Cg2cingulate cortex area 2Dendorsal endopiriform nucleusDIdysgranular insular cortexDPdorsal peduncular cortexDZprimary somatosensory cortex dorsal zoneEctectorhinal cortexGIgranular insular cortexILinfralimbic cortexLOlateral orbital cortexM1primary motor cortexM2secondary motor cortexMCmotor cortexMOmedial orbital cortexPFCprefrontal cortexPrhperirhinal cortexPrLprelimbic cortexRSGretrosplenial granular cortexS1primary somatosensory cortexS1Trprimary somatosensory cortex trunk regionS2secondary somatosensory cortexSCsomatosensory cortexTeAtemporal association cortexV1Bprimary visual cortex, binocular areaV1Mprimary visual cortex, monocular areaV2Lsecondary visual cortex, lateral areaV2Msecondary visual cortex, mediolateral areaVCvisual cortexVOventral orbital cortex. ER -