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Population diversity and function of hyperpolarization-activated current in olfactory bulb mitral cells
Kamilla Angelo1, Troy W Margrie
1Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London WC1E 6BT, United Kingdom; Department of Neuroscience and Pharmacology, Faculty of Health Sciences, University of Copenhagen, Denmark.
Scientific Reports
|February 23, 2012
Summary
Mitral cells show diverse expression of hyperpolarization-activated cyclic nucleotide gated (HCN) channel currents, impacting their electrical activity and odor representation. This biophysical diversity influences neuronal integration and dynamic range.
Area of Science:
- Neuroscience
- Cellular Electrophysiology
Background:
- Neurons possess diverse intrinsic properties influencing neural computations.
- Quantifying biophysical diversity and its functional impact in neurons remains underexplored.
Purpose of the Study:
- To investigate the heterogeneity of mitral cells in their expression of hyperpolarization-activated currents.
- To determine the functional consequences of this biophysical diversity on neuronal integration and odor representation.
Main Methods:
- In vivo and in vitro whole-cell recordings were utilized.
- Analysis focused on rebound depolarization (sag) mediated by ZD7288-sensitive currents, characteristic of hyperpolarization-activated cyclic nucleotide gated (HCN) channels.
Main Results:
- Mitral cells exhibit significant heterogeneity in sag potential amplitude, mediated by HCN channels.
- Cells with larger sag potentials display increased membrane noise, lower rheobase, and more regular firing patterns.
- Absence of sag correlates with distinct electrophysiological properties compared to cells with sag.
Conclusions:
- Variability in sag potential amplitude reflects functional diversity within the mitral cell population.
- This cell-to-cell variability in biophysical properties enhances the dynamic range of odor representation.
- Understanding mitral cell heterogeneity is crucial for comprehending olfactory processing.
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