Optimizing computer models of corticospinal neurons to replicate in vitro dynamics
| Autor: | Michele Migliore, Gordon M. Shepherd, Samuel A. Neymotin, Benjamin A. Suter, William W. Lytton, Salvador Dura-Bernal |
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| Rok vydání: | 2017 |
| Předmět: |
0301 basic medicine
Patch-Clamp Techniques Physiology Models Neurological Biophysics Pyramidal Tracts Action Potentials Neocortex In Vitro Techniques Mice 03 medical and health sciences 0302 clinical medicine Corticospinal neuron Layer 5 HCN channel medicine Animals Computer Simulation Neurons Physics Neurotransmitter Agents biology General Neuroscience Dynamics (mechanics) Resonance Replicate Electric Stimulation In vitro Mice Inbred C57BL 030104 developmental biology medicine.anatomical_structure Animals Newborn Nonlinear Dynamics biology.protein Motor cortex Neuroscience 030217 neurology & neurosurgery Hyperpolarization-activated cyclic nucleotidegated channel Research Article |
| Zdroj: | Journal of neurophysiology 117 (2017): 148–162. doi:10.1152/jn.00570.2016 info:cnr-pdr/source/autori:Neymotin SA, Suter BA, Dura-Bernal S, Shepherd GM, Migliore M, Lytton WW/titolo:Optimizing computer models of corticospinal neurons to replicate in vitro dynamics/doi:10.1152%2Fjn.00570.2016/rivista:Journal of neurophysiology/anno:2017/pagina_da:148/pagina_a:162/intervallo_pagine:148–162/volume:117 |
| ISSN: | 1522-1598 0022-3077 |
| Popis: | Corticospinal neurons (SPI), thick-tufted pyramidal neurons in motor cortex layer 5B that project caudally via the medullary pyramids, display distinct class-specific electrophysiological properties in vitro: strong sag with hyperpolarization, lack of adaptation, and a nearly linear frequency-current ( F– I) relationship. We used our electrophysiological data to produce a pair of large archives of SPI neuron computer models in two model classes: 1) detailed models with full reconstruction; and 2) simplified models with six compartments. We used a PRAXIS and an evolutionary multiobjective optimization (EMO) in sequence to determine ion channel conductances. EMO selected good models from each of the two model classes to form the two model archives. Archived models showed tradeoffs across fitness functions. For example, parameters that produced excellent F– I fit produced a less-optimal fit for interspike voltage trajectory. Because of these tradeoffs, there was no single best model but rather models that would be best for particular usages for either single neuron or network explorations. Further exploration of exemplar models with strong F– I fit demonstrated that both the detailed and simple models produced excellent matches to the experimental data. Although dendritic ion identities and densities cannot yet be fully determined experimentally, we explored the consequences of a demonstrated proximal to distal density gradient of Ih, demonstrating that this would lead to a gradient of resonance properties with increased resonant frequencies more distally. We suggest that this dynamical feature could serve to make the cell particularly responsive to major frequency bands that differ by cortical layer. NEW & NOTEWORTHY We developed models of motor cortex corticospinal neurons that replicate in vitro dynamics, including hyperpolarization-induced sag and realistic firing patterns. Models demonstrated resonance in response to synaptic stimulation, with resonance frequency increasing in apical dendrites with increasing distance from soma, matching the increasing oscillation frequencies spanning deep to superficial cortical layers. This gradient may enable specific corticospinal neuron dendrites to entrain to relevant oscillations in different cortical layers, contributing to appropriate motor output commands. |
| Databáze: | OpenAIRE |
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