Aberrant thalamocortical coherence in an animal model of tinnitus

Electrophysiological studies from humans suggest that the phantom sound of tinnitus is associated with abnormal thalamocortical neural oscillations. However, tinnitus models have seldom been tested in animal models where it is possible to simultaneously assess the neural oscillatory activity between the thalamus and auditory cortex. To explore this issue, we used multichannel electrodes to examine the oscillatory behavior of local field potentials recorded in the rat medial geniculate body (MBG) and primary auditory cortex (A1) before and after administering a dose of sodium salicylate (SS) that reliably induces tinnitus. In the MGB, SS reduced power and coherence in theta, alpha and beta oscillations, but increased coherence in the gamma band. Within A1, SS significantly decreased power and coherence between theta and alpha bands, but increased power and coherence in the gamma band. When coherence was measured between one electrode in the MGB and another in A1, SS decreased coherence in beta, alpha and t...