Biophysically realistic neuron models for simulation of cortical stimulation.

Area of Science:

• Computational neuroscience
• Electrophysiology
• Biophysics

Background:

• Understanding neural responses to electromagnetic fields is crucial for developing effective brain stimulation therapies.
• Existing models often lack detailed biophysical and morphological realism for human and rat cortical neurons.

Purpose of the Study:

• To develop and utilize computational models of human and rat cortical neurons to simulate neural responses to electromagnetic field stimulation.
• To investigate the influence of neuronal morphology on the response to different cortical stimulation modalities.

Main Methods:

• Adapted Blue Brain model neurons to incorporate detailed biophysical and geometric properties of rat and human cortical neurons.
• Coupled neuron models with exogenous electric fields (E-fields) for simulations.
• Characterized single-cell responses to intracortical microstimulation (ICMS) and uniform E-fields (DC and pulsed).

Main Results:

• Model neuron responses to ICMS (strength-duration, current-distance) matched experimental data.
• Subthreshold polarization of cell bodies and axon terminals by uniform DC E-fields aligned with prior findings.
• Axon collateral terminals exhibited the lowest stimulation thresholds, influenced by axonal morphology (myelination, diameter, branching).

Conclusions:

• Neuronal morphology, particularly axonal arbor features, critically affects responses to cortical stimulation.
• The developed models provide a valuable tool for studying various cortical stimulation techniques with detailed E-field characteristics.