Tinnitus and hyperacusis involve hyperactivity and enhanced connectivity in auditory-limbic-arousal-cerebellar network
- Southeast University, China
- Dalhousie University, Canada
- University at Buffalo, The State University of New York, United States
Figures
Figure 1
SS-induced tinnitus, hyperacusis, and startle reflex hyperactivity.
(A and B) 2AFC-tinnitus task for two representative rats during baseline days B1–B4, during Saline (SAL) treatment, during baseline days B6–B9, 2 hr post-sodium salicylate (SS), and days P1–P4 …
Figure 2
SS depresses cochlear potentials but enhances central auditory evoked responses.
Effects of 300 mg/kg SS on peripheral and central electrophysiological measures. (A) Mean (+SEM, n = 5) compound action potential (CAP) input/output function (average of 6, 8, 12, 16, 20, 24, 30, …
Figure 3
SS enhances and depresses amplitude of low-frequency fluctuations (ALFF) in specific CNS regions.
Panels A (most caudal) through K (most rostral) show MR images of rat brain. Significant differences in ALFF between the SS group vs Saline group 2 hr post-treatment. Thresholds set at a corrected p …
Figure 4 with 1 supplement
SS alters functional connectivity (FC) in specific brain resions.
ROI FC heat maps showing the regions of the brain where SS induced a statistically significant increase in FC with the ROI placed in the ACx (top row), MGB (middle row), or inferior colliculus (IC) …
Figure 4—figure supplement 1
The ALFF and FC data (seeds: ACx, MGB, and IC) for baseline and after SS application separately.
https://doi.org/10.7554/eLife.06576.008
Figure 5
Tinnitus–hyperacusis network model.
Schematic showing some of the major centers in the auditory pathway and areas in the CNS showing increased FC with the auditory cortex (ACx). Black lines show the neural transmission path from the …
Tables
Table 1
SS-induced changes in amplitude of low-frequency fluctuations (ALFF); SS group vs Saline group; p < 0.001 corrected for multiple comparisons
| Brain region | Left | Right | ||
|---|---|---|---|---|
| Cluster size | t-value | Cluster size | t-value | |
| ALFF increased | ||||
| ACx | 167 | 3.812 | 178 | 3.746 |
| IC | 72 | 3.383 | 68 | 3.473 |
| MGB | 52 | 3.432 | 48 | 3.339 |
| SSCx | 37 | 3.383 | 40 | 3.402 |
| VCx | 32 | 3.342 | 39 | 3.312 |
| SC | 40 | 4.123 | 43 | 4.094 |
| AMY | 61 | 4.192 | 60 | 3.923 |
| RN/PnO | 35 | 3.249 | 28 | 3.290 |
| PnO/PMr | 12 | 3.498 | 10 | 3.313 |
| PFL | 38 | 3.349 | 37 | 3.292 |
| CB4 | 38 | 3.349 | 37 | 3.292 |
| ALFF decreased | ||||
| HIP | 108 | −4.087 | 92 | −4.002 |
| CPu | 72 | −3.772 | 71 | −3.741 |
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Abbreviations: auditory cortex (ACx), inferior colliculus (IC), medial geniculate body (MGB), somatosensory cortex (SSCx), visual cortex (VCx), superior colliculi (SC), amygdala (AMY), gigantocellular reticular nucleus (RN), pontine reticular nucleus oral (PnO), paramedian raphe nucleus (PMr), parafloccular lobe of cerebellum (PFL), cerebellum lobule 4 (CB4), hippocampus (HIP), caudate-putamen (CPu), sodium salicylate (SS).
Table 2
SS-induced increases in functional connectivity (FC); p < 0.001 corrected for multiple comparisons
| Seed region | Brain region | Left | Right | ||
|---|---|---|---|---|---|
| Cluster size | t-value | Cluster size | t-value | ||
| ACx | MGB | 62 | 3.900 | 70 | 3.859 |
| IC | 82 | 3.912 | 88 | 3.632 | |
| AMY | 67 | 3.897 | 68 | 3.839 | |
| RN | 52 | 3.983 | 48 | 3.902 | |
| PFL | 39 | 3.992 | 35 | 3.954 | |
| CB4 | 51 | 4.066 | 53 | 4.070 | |
| MGB | ACx | 195 | 4.074 | 210 | 4.084 |
| HIP | 162 | 4.032 | 178 | 4.109 | |
| IC | MGB | 72 | 4.098 | 60 | 4.013 |
| HIP | 140 | 4.064 | 131 | 3.904 | |
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Abbreviations: medial geniculate body (MGB), inferior colliculus (IC), amygdala (AMY), reticular nucleus (RN), parafloccular lobe of cerebellum (PFL), cerebellum lobule 4 (CB4), auditory cortex (ACx), hippocampus (HIP), sodium salicylate (SS).
