Theγ-aminobutyric acid neurons (GABAergic neurons) in the inferior colliculus are classiifed into various patts based on their intrin-sic electrical properties to a constant current injection. Although this classiifcation is associated with physiological function, the exact role for neurons with various ifring patts in acoustic processing remains poorly understood. In the present study, we analyzed characteristics of inferior colliculus neuronsin vitro, and recorded responses to stimulation of the dorsal nucleus of the lateral lemniscus using the whole-cell patch clamp technique. Seven inferior colliculus neurons were tested and were classiifed into two ifring patts: sustained-regular (n = 4) and sustained-adapting ifring patts (n = 3). The majority of inferior colliculus neurons exhibited slight changes in response to stimulation and bicuculline. The responses of one neuron with a sustained-adapting ifring patt were suppressed after stimulation, but recovered to normal levels following application of theγ-aminobutyric acid receptor antagonist. One neuron with a sustained-regular patt showed suppressed stimulation responses, which were not affected by bicuculline. Results suggest that GABAergic neurons in the inferior colliculus exhibit sustained-regular or sustained-adapting ifring patts. Additionally, GABAergic projections from the dorsal nu-cleus of the lateral lemniscus to the inferior colliculus are associated with sound localization. The different neuronal responses of various ifring patts suggest a role in sound localization. A better understanding of these mechanisms and functions will provide better clinical treatment paradigms for hearing deifciencies.