title: Increased striatal functional connectivity with auditory cortex in tinnitus.
abstract: Tinnitus is a common auditory perceptual disorder whose neural substrates are under intense debate. One physiologically based model posits the dorsal striatum to play a key role in gating auditory phantoms to perceptual awareness. Here, we directly test this model along with the roles of auditory and auditory-limbic networks in tinnitus non-invasively by comparing resting-state fMRI functional connectivity patterns in chronic tinnitus patients against matched control subjects without hearing loss. We assess resting-state functional connectivity of the caudate dorsal striatum (area LC), caudate head (CH), nucleus accumbens (NA), and primary auditory cortex (A1) to determine patterns of abnormal connectivity. In chronic tinnitus, increases in ipsilateral striatal-auditory cortical connectivity are found consistently only in area LC. Other patterns of increased connectivity are as follows: (1) right striatal area LC, A1, CH, and NA with parietal cortex, (2) left and right CHs with dorsal pre-frontal cortex, (3) NA and A1 with cerebellum, hippocampus, visual and ventral pre-frontal cortex. Those findings provide further support for a striatal gating model of tinnitus, where dysfunctionally permissive area LC enables auditory phantoms to reach perceptual awareness.
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California at San Francisco, San Francisco CA, USA.
authors.forename: Leighton B
authors.initials: LB
authors.lastname: Hinkley
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California at San Francisco, San Francisco CA, USA.
authors.forename: Danielle
authors.initials: D
authors.lastname: Mizuiri
authors.affiliation: Department of Community Health Systems, School of Nursing, University of California at San Francisco, San Francisco CA, USA.
authors.forename: OiSaeng
authors.initials: O
authors.lastname: Hong
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California at San Francisco, San Francisco CA, USA ; Department of Otolaryngology-Head and Neck Surgery, University of California at San Francisco, San Francisco CA, USA.
authors.forename: Srikantan S
authors.initials: SS
authors.lastname: Nagarajan
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, University of California at San Francisco, San Francisco CA, USA ; Surgical Services, San Francisco Veterans Affairs Medical Center, San Francisco CA, USA.
authors.forename: Steven W
authors.initials: SW
authors.lastname: Cheung
keywords: auditory cortex; functional connectivity; resting-state fMRI; striatum; tinnitus