Figure 9. Experiment 2 glutamatergic agonist effect on unexposed rats with no evidence of tinnitus.

The glutamatergic agonist cocktail was delivered to the right PFL of unexposed rats with no evidence of tinnitus (open circular data points). Unexposed and exposed control groups are depicted as in Figure 7. Pre-drug data are shown in the upper left panel. The agonist cocktail induced a significant tinnitus-like downshift in the function of unexposed animals (upper right panel) after 72 hrs, although, as before, their tinnitus did not attain the same level as the exposed group with tinnitus (F statistics in panel). This tinnitus-like induction gradually washed out over the course of treatment (lower panels, left to right).