Reduced oriens-lacunosum/moleculare cell model identifies biophysical current balances for in vivo theta frequency spiking resonance

Zhenyang Sun; David Crompton; Milad Lankarany; Frances K Skinner

doi:10.3389/fncir.2023.1076761

Reduced oriens-lacunosum/moleculare cell model identifies biophysical current balances for in vivo theta frequency spiking resonance

Front Neural Circuits. 2023 Feb 3:17:1076761. doi: 10.3389/fncir.2023.1076761. eCollection 2023.

Authors

Zhenyang Sun¹, David Crompton^{1

2}, Milad Lankarany^{1

2

3

4}, Frances K Skinner^{1

5}

Affiliations

¹ Krembil Brain Institute, University Health Network, Toronto, ON, Canada.
² Institute of Biomedical Engineering, University of Toronto, Toronto, ON, Canada.
³ Department of Physiology, University of Toronto, Toronto, ON, Canada.
⁴ KITE, Toronto Rehabilitation Institute, University Health Network, Toronto, ON, Canada.
⁵ Departments of Medicine (Neurology) and Physiology, University of Toronto, Toronto, ON, Canada.

Abstract

Conductance-based models have played an important role in the development of modern neuroscience. These mathematical models are powerful "tools" that enable theoretical explorations in experimentally untenable situations, and can lead to the development of novel hypotheses and predictions. With advances in cell imaging and computational power, multi-compartment models with morphological accuracy are becoming common practice. However, as more biological details are added, they make extensive explorations and analyses more challenging largely due to their huge computational expense. Here, we focus on oriens-lacunosum/moleculare (OLM) cell models. OLM cells can contribute to functionally relevant theta rhythms in the hippocampus by virtue of their ability to express spiking resonance at theta frequencies, but what characteristics underlie this is far from clear. We converted a previously developed detailed multi-compartment OLM cell model into a reduced single compartment model that retained biophysical fidelity with its underlying ion currents. We showed that the reduced OLM cell model can capture complex output that includes spiking resonance in in vivo-like scenarios as previously obtained with the multi-compartment model. Using the reduced model, we were able to greatly expand our in vivo-like scenarios. Applying spike-triggered average analyses, we were able to to determine that it is a combination of hyperpolarization-activated cation and muscarinic type potassium currents that specifically allow OLM cells to exhibit spiking resonance at theta frequencies. Further, we developed a robust Kalman Filtering (KF) method to estimate parameters of the reduced model in real-time. We showed that it may be possible to directly estimate conductance parameters from experiments since this KF method can reliably extract parameter values from model voltage recordings. Overall, our work showcases how the contribution of cellular biophysical current details could be determined and assessed for spiking resonance. As well, our work shows that it may be possible to directly extract these parameters from current clamp voltage recordings.

Keywords: Kalman Filter; M-current; h-current; hippocampus; interneuron; parameter estimation; spiking resonance; theta rhythm.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Biophysics
Hippocampus* / physiology
Interneurons* / physiology
Models, Theoretical
Theta Rhythm / physiology

Grants and funding

This research was supported by the Natural Sciences and Engineering Research Council of Canada (NSERC) Discovery Grants (RGPIN-2016-06182 to FS and RGPIN-2020-05868 to ML) and an NSERC USRA to ZS.