Plasticity of binaural interaction in the cat inferior colliculus

Responses of single neurones in the inferior colliculus (IC) to acoustic interaural intensity difference (IID) were examined in normal, adult cats and in cats that had been reared for 3--4 months, either from birth or as adults, with unilateral ligation of the external meatus. There were significantly fewer units displaying IID sensitivity in either of the ligated groups than there were in the normal group. The loss of IID sensitivity in the ligated animals reflected a diminished inhibitory input from the non-ligated ear.