Related Experiment Video
Updated: Sep 27, 2026

Manufacturing and Using Piggy-back Multibarrel Electrodes for In vivo Pharmacological Manipulations of Neural Responses
Published on: January 18, 2013
Binaural interaction in the inferior colliculus of the big brown bat, Eptesicus fuscus
1Division of Biological Sciences and Interdisciplinary Neuroscience Program, The University of Missouri-Columbia, Columbia, MO 65211, USA.
Abstract:
Binaural interaction plays an important role in shaping response properties of central auditory neurons. Using single unit recording and iontophoresis, we examined frequency tuning curves (FTCs), interaural intensity difference (IID) curves, and rate-intensity functions of inferior collicular (IC) neurons of the big brown bat, Eptesicus fuscus, under closed system or free field stimulation conditions. We isolated 46 EI (excitation-inhibition), 24 EO (monaural excitation) and 6 EE (excitation-excitation) neurons. Inhibitory FTCs of EI neurons plotted under ipsilateral sound stimulation fell within (n=10, 22%), partly overlapped (n=26, 56%), or almost entirely encompassed (n=10, 22%) excitatory FTCs plotted by contralateral sound stimulation. The discharge rate of EI neurons was a sigmoid function of IID. The peak discharge rate occurred at IIDs at which contralateral sound stimulation was stronger than ipsilateral sound stimulation. Application of bicuculline, an antagonist for gamma-aminobutyric acid A receptors, raised the IID curves and broadened the excitatory FTCs but partly or completely abolished the ipsilateral inhibitory FTCs. For EE neurons, excitatory FTCs and rate-intensity functions plotted by contralateral sound stimulation were always broader and higher than those plotted by ipsilateral sound stimulation. The sharpness of FTCs of EI neurons was significantly greater at ipsilateral 30 degrees than at 30 degrees contralateral. This direction-dependent frequency tuning was effectively abolished by occlusion of the ipsilateral ear. Possible mechanisms underlying these observations are discussed.
More Related Videos
10:50Behavioral Determination of Stimulus Pair Discrimination of Auditory Acoustic and Electrical Stimuli Using a Classical Conditioning and Heart-rate Approach
Published on: June 6, 2012
07:40Dissection of the Auditory Bulla in Postnatal Mice: Isolation of the Middle Ear Bones and Histological Analysis
Published on: January 4, 2017
Related Concept Videos
The Cochlea
Auditory Pathway
When viewed cross-sectionally, the cochlea reveals the scala vestibuli and scala tympani flanking the...
The Auditory Ossicles
The aptly named stapes look very much like a stirrup. The three ossicles are unique to mammals, and each plays a role in...
Anatomy of the Ear
Equilibrium and Balance
Hair Cells