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Updated: Oct 18, 2026

Prolonged Incubation of Acute Neuronal Tissue for Electrophysiology and Calcium-imaging
Published on: February 15, 2017
Hyperpolarization-activated cyclic nucleotide-gated channels preserve excitability in ON-bipolar cells after
Jung Woong Chu1, Bokeum Kang2, Kyungmin Kim2
1Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul 02792, Republic of Korea; Division of Bio-Medical Science & Technology, University of Science and Technology KIST School, Seoul 02792, Republic of Korea.
Abstract:
Retinal degeneration leads to extensive remodeling of inner retinal circuits following photoreceptor loss, but the intrinsic membrane properties of surviving bipolar cells remain incompletely understood. Here, we investigated the expression and functional contribution of hyperpolarization-activated cyclic nucleotide-gated (HCN) channels in ON-bipolar cells using the rd10 mouse model of retinitis pigmentosa. High-resolution fluorescence in situ hybridization showed no significant differences in Hcn1, Hcn2, and Hcn4 transcript levels between wild-type (WT) and rd10 bipolar cells. Whole-cell patch-clamp recordings detected hyperpolarization-activated inward currents consistent with Ih in both WT and rd10 ON-bipolar cells with no significant differences. In current-clamp recordings, the recovery of membrane potential following hyperpolarizing current pulses was significantly slowed by HCN channel blockers (ivabradine and ZD7288) in both genotypes. These findings indicate that HCN-sensitive conductances contribute to membrane potential recovery in ON-bipolar cells and remain detectable after photoreceptor degeneration.
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