Involvement of GABAergic inhibition in forward masking induced by weak noise on frequency tuning of inferior colliculus

To study the effect of GABAergic inhibition on forward masking of weak noise and the mechanism underlying this temporal integration,this paper use weak white noise which is relative to 5 dB beyond minimum threshold(reMT+5) and 80 ms as forward masker.Under free field stimulation conditions,the changes in neuronal frequency tuning resulted from forward masking sound are examined.In addition, the paper observes the effect of micro-ionophoresis of BIC to the sharpened neurons,and finds that forward masking sharpens frequency tuning curves(FTCs) of most neurons(P0.01).After micro-ionophoresis of BIC,the inhibitory rate of weak noise decreases.It's believed that the GABAergic inhibition is involved in forward masking induced by weak white noise on the inferior colliculus.