HCN2 Gene - Hyperpolarization-activated Cyclic Nucleotide-gated Channel 2

HCN2 Gene - Hyperpolarization-activated Cyclic Nucleotide-gated Channel 2

Introduction

Hcn2 Gene Hyperpolarization Activated Cyclic Nucleotide Gated Channel 2 is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.

--- [@biel2009]
title: HCN2 Gene [@difrancesco2020]
description: Hyperpolarization-activated cyclic nucleotide-gated channel 2 [@ludwig2003]

--- [@he2014]

<div class="infobox infobox-gene">
<table>
<tr><th colspan="2" style="background:#f0f0f0;">HCN2 Gene</th></tr>
<tr><td><strong>Symbol</strong></td><td>HCN2</td></tr>
<tr><td><strong>Full Name</strong></td><td>Hyperpolarization Activated Cyclic Nucleotide Gated Potassium Channel 2</td></tr>
<tr><td><strong>Chromosomal Location</strong></td><td>19q13.4</td></tr>
<tr><td><strong>NCBI Gene ID</strong></td><td><a href="https://www.ncbi.nlm.nih.gov/gene/6138" target="_blank">6138</a></td></tr>
<tr><td><strong>OMIM</strong></td><td><a href="https://www.omim.org/entry/616383" target="_blank">616383</a></td></tr>
<tr><td><strong>Ensembl ID</strong></td><td>ENSG00000145214</td></tr>
<tr><td><strong>UniProt ID</strong></td><td><a href="https://www.uniprot.org/uniprot/Q9P0R3" target="_blank">Q9UQB8</a></td></tr>
<tr><td><strong>Associated Diseases</strong></td><td>Epilepsy, Cardiac Arrhythmia, Parkinson's Disease, Sinoatrial Node Dysfunction</td></tr>
</table>
</div>

Overview

HCN2 Gene - Hyperpolarization-activated Cyclic Nucleotide-gated Channel 2

Introduction

Hcn2 Gene Hyperpolarization Activated Cyclic Nucleotide Gated Channel 2 is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.

--- [@biel2009]
title: HCN2 Gene [@difrancesco2020]
description: Hyperpolarization-activated cyclic nucleotide-gated channel 2 [@ludwig2003]

--- [@he2014]

<div class="infobox infobox-gene">
<table>
<tr><th colspan="2" style="background:#f0f0f0;">HCN2 Gene</th></tr>
<tr><td><strong>Symbol</strong></td><td>HCN2</td></tr>
<tr><td><strong>Full Name</strong></td><td>Hyperpolarization Activated Cyclic Nucleotide Gated Potassium Channel 2</td></tr>
<tr><td><strong>Chromosomal Location</strong></td><td>19q13.4</td></tr>
<tr><td><strong>NCBI Gene ID</strong></td><td><a href="https://www.ncbi.nlm.nih.gov/gene/6138" target="_blank">6138</a></td></tr>
<tr><td><strong>OMIM</strong></td><td><a href="https://www.omim.org/entry/616383" target="_blank">616383</a></td></tr>
<tr><td><strong>Ensembl ID</strong></td><td>ENSG00000145214</td></tr>
<tr><td><strong>UniProt ID</strong></td><td><a href="https://www.uniprot.org/uniprot/Q9P0R3" target="_blank">Q9UQB8</a></td></tr>
<tr><td><strong>Associated Diseases</strong></td><td>Epilepsy, Cardiac Arrhythmia, Parkinson's Disease, Sinoatrial Node Dysfunction</td></tr>
</table>
</div>

Overview

HCN2 encodes the Hyperpolarization-activated Cyclic Nucleotide-gated channel 2, a member of the HCN channel family that generates the hyperpolarization-activated current (Ih). These channels play crucial roles in neuronal and cardiac pacemaking, synaptic integration, and resonance.

Function

HCN2 channels are voltage-gated cation channels that pass both Na+ and K+ currents with unusual gating properties.

Molecular Functions

• Pacemaker Current: Generates Ih, a depolarizing current activated by hyperpolarization
• Resting Potential: Contributes to setting and stabilizing the resting membrane potential
• Synaptic Integration: Modulates dendritic integration and synaptic plasticity
• Temporal Processing: Enables neuronal resonance and filter properties
• Channel Properties:
• Voltage range: Activated by hyperpolarization below -50 mV
• cAMP modulation: Direct binding accelerates activation
• Permeability: Na+/K+ mix (roughly 1:4)
• Single channel conductance: ~10 pS

Expression Pattern

In the brain, HCN2 is expressed in:

• Thalamus: Very high expression in thalamocortical [neurons](/entities/neurons)
• [Cortex](/brain-regions/cortex): Layer 5 pyramidal neurons, interneurons
• [Hippocampus](/brain-regions/hippocampus): CA1 pyramidal cells, dentate gyrus granule cells
• Basal Ganglia: Striatum, substantia nigra
• Brainstem: Various nuclei including locus coeruleus
• Cerebellum: Purkinje cells, deep nuclei

Disease Associations

Epilepsy

• Thalamic Expression: HCN2 dysfunction contributes to thalamocortical hyperexcitability
• Absence Seizures: Reduced Ih alters thalamic oscillations leading to spike-wave discharges
• Therapeutic Target: HCN channel blockers (ivabradine) being investigated

Cardiac Arrhythmias

• SA Node Function: HCN2 critical for cardiac pacemaking
• Heart Rate: HCN2 knockout mice show bradycardia
• Sinus Node Dysfunction: HCN2 variants associated with sick sinus syndrome

Parkinson's Disease

• Basal Ganglia: Altered HCN channel function in PD models
• Therapeutic Potential: HCN modulators may improve motor symptoms
• Dyskinesia: Role in L-DOPA-induced dyskinesias under investigation

Neurological Disorders

• Neuropathic Pain: HCN2 in sensory neurons contributes to pain signaling
• Migraine: HCN channel involvement in cortical spreading depression
• Tremor: HCN function in olivocerebellar circuits

Therapeutic Implications

Therapeutic Strategies

Drug Development

• Ivabradine: FDA-approved for heart failure, being repurposed for epilepsy
• ZD7288: Experimental HCN blocker used in research
• Lamotrigine: Anticonvulsant that blocks HCN currents

Key Publications

See Also

• [Parkinson's Disease](/diseases/parkinsons-disease)
• [Epilepsy](/diseases/epilepsy)
• [Thalamus](/brain-regions/thalamus)
• [Substantia Nigra](/cell-types/substantia-nigra-dopaminergic-neurons)
• [Ion Channelopathies](/mechanisms/ion-channelopathies)

External Links

• [NCBI Gene: HCN2](https://www.ncbi.nlm.nih.gov/gene/6138)
• [UniProt: HCN2 (Q9UQB8)](https://www.uniprot.org/uniprot/Q9UQB8)
• [Ensembl: HCN2](https://www.ensembl.org/Homo_sapiens/Gene/Summary?g=ENSG00000145214)
• [OMIM: HCN2](https://www.omim.org/entry/616383)

Background

The study of Hcn2 Gene Hyperpolarization Activated Cyclic Nucleotide Gated Channel 2 has evolved significantly over the past decades. Research in this area has revealed important insights into the underlying mechanisms of neurodegeneration and continues to drive therapeutic development.

Historical context and key discoveries in this field have shaped our current understanding and will continue to guide future research directions.

Brain Atlas Resources

• [Allen Human Brain Atlas - HCN2 Expression](https://human.brain-map.org/microarray/search/show?search_term=HCN2)
• [Allen Cell Type Atlas - HCN2](https://celltypes.brain-map.org/)
• [BrainSpan - HCN2 Developmental Expression](https://brainspan.org/)
• [Allen Mouse Brain Atlas - HCN2](https://mouse.brain-map.org/)

References

Pathway Diagram

The following diagram shows the key molecular relationships involving HCN2 Gene - Hyperpolarization-activated Cyclic Nucleotide-gated Channel 2 discovered through SciDEX knowledge graph analysis: