Related Experiment Video
Updated: Aug 15, 2026

Preparation and Culture of Chicken Auditory Brainstem Slices
Published on: March 21, 2011
Hyperpolarization-activated cyclic nucleotide-gated cation channels regulate auditory coincidence detection in
Rei Yamada1, Hiroshi Kuba, Takahiro M Ishii
1Department of Physiology, Faculty of Medicine, Kyoto University, Kyoto 606-8501, Japan.
Abstract:
Coincidence detection of bilateral acoustic signals in nucleus laminaris (NL) is the first step in azimuthal sound source localization in birds. Here, we demonstrate graded expression of hyperpolarization-activated cyclic nucleotide-gated (HCN) cation channels along the tonotopic axis of NL and its role in the regulation of coincidence detection. Expression of HCN1 and HCN2, but not HCN3 or HCN4, was detected in NL. Based on measurement of both subtype mRNA and protein, HCN1 varied along the tonotopic axis and was minimal in high-characteristic frequency (CF) neurons. In contrast, HCN2 was evenly distributed. The resting conductance was larger and the steady-state activation curve of Ih was more positive in neurons of middle to low CF than those of high CF, consistent with the predominance of HCN1 channels in these neurons. Application of 8-Br-cAMP or noradrenaline generated a depolarizing shift of the Ih voltage activation curve. This shift was larger in neurons of high CF than in those of middle CF. The shift in the activation voltage of Ih depolarized the resting membrane, accelerated the EPSP time course, and significantly improved the coincidence detection in neurons of high CF, suggesting that Ih may improve the localization of sound sources.
More Related Videos
Related Concept Videos
Hair Cells
The Cochlea
Auditory Pathway
When viewed cross-sectionally, the cochlea reveals the scala vestibuli and scala tympani flanking the...
Anatomy of the Ear
The Role of Ion Channels in Neuronal Computation
Sometimes a single EPSP is strong enough to induce an action potential in the postsynaptic neuron. However, multiple presynaptic inputs must often create EPSPs around the same time for the postsynaptic neuron to be sufficiently depolarized to fire an action potential.

