An ephaptic transmission model of CA3 pyramidal cells: an investigation into electric field effects.

Cognitive neurodynamics · 2014 · Mixed · Low evidence

← Research stream

MixedLow evidencePaper 3075

Study snapshot

PublicationCognitive neurodynamics · 2014

Study typeother

Reported directionMixed

Evidence ratingLow

Abstract

Extracellular electric fields existing throughout the living brain affect the neural coding and information processing via ephaptic transmission, independent of synapses. A two-compartment whole field effect model (WFEM) of pyramidal neurons embedded within a resistive array which simulates the extracellular medium i.e. ephapse is developed to study the effects of electric field on neuronal behaviors. We derive the two linearized filed effect models (LFEM-1 and LFEM-2) from WFEM at the stable resting state. Through matching these simplified models to the subthreshold membrane response in experiments of the resting pyramidal cells exposed to applied electric fields, we not only verify our proposed model's validity but also found the key parameters which dominate subthreshold frequency response characteristic. Moreover, we find and give its underlying biophysical mechanism that the unsymmetrical properties of active ion channels results in the very different low-frequency response of somatic and dendritic compartments. Following, WFEM is used to investigate both direct-current (DC) and alternating-current field effect on the neural firing patterns by bifurcation analyses. We present that DC electric field could modulate neuronal excitability, with the positive field improving the excitability, the modest negative field suppressing the excitability, but interestingly, the larger negative field re-exciting the neuron back into spiking behavior. The neuron exposed to the sinusoidal electric field exhibits abundant firing patterns sensitive to the input frequency and intensity. In addition, the electrical properties of ephapse can modulate the efficacy of field effect. Our simulated results are qualitatively in line with the relevant experimental results and can explain some experimental phenomena. Furthermore, they are helpful to provide the predictions which can be tested in future experiments.

Machine Enhanced Logic

AI evidence extraction

Structured fields below were generated from the paper’s abstract and metadata to make the evidence easier to inspect. Automated extraction may be incomplete or incorrect; verify important details against the original paper.

Study typeother

Effect directionmixed

PopulationNot supplied

Sample sizeNot supplied

ExposureNot supplied

Evidence strengthLowConfidence: 74% · Peer reviewed: yes

Main findings

The authors developed a two-compartment computational model of CA3 pyramidal neurons embedded in a resistive extracellular medium to study ephaptic (field) effects. Model behavior was matched to experimental subthreshold responses of resting pyramidal cells exposed to applied electric fields, and simulations suggested DC fields can modulate excitability (positive fields increasing excitability; modest negative fields decreasing excitability; larger negative fields re-inducing spiking), while sinusoidal fields produced frequency- and intensity-sensitive firing patterns; ephapse electrical properties also modulated field-effect efficacy.

Outcomes measured

neuronal excitability
subthreshold membrane response / frequency response characteristics
neural firing patterns (spiking behavior)
ephaptic transmission / field effects on CA3 pyramidal cell compartments (somatic vs dendritic)

Limitations

Computational/modeling study; results depend on model structure and parameter choices
No quantitative exposure metrics (field strength, frequency values) provided in the abstract
Experimental comparison is described qualitatively; details of the referenced experiments are not provided in the abstract

View raw extracted JSON

{
  "study_type": "other",
  "exposure": {
    "band": null,
    "source": "extracellular electric fields (applied electric fields; DC and sinusoidal AC)",
    "frequency_mhz": null,
    "sar_wkg": null,
    "duration": null
  },
  "population": null,
  "sample_size": null,
  "outcomes": [
    "neuronal excitability",
    "subthreshold membrane response / frequency response characteristics",
    "neural firing patterns (spiking behavior)",
    "ephaptic transmission / field effects on CA3 pyramidal cell compartments (somatic vs dendritic)"
  ],
  "main_findings": "The authors developed a two-compartment computational model of CA3 pyramidal neurons embedded in a resistive extracellular medium to study ephaptic (field) effects. Model behavior was matched to experimental subthreshold responses of resting pyramidal cells exposed to applied electric fields, and simulations suggested DC fields can modulate excitability (positive fields increasing excitability; modest negative fields decreasing excitability; larger negative fields re-inducing spiking), while sinusoidal fields produced frequency- and intensity-sensitive firing patterns; ephapse electrical properties also modulated field-effect efficacy.",
  "effect_direction": "mixed",
  "limitations": [
    "Computational/modeling study; results depend on model structure and parameter choices",
    "No quantitative exposure metrics (field strength, frequency values) provided in the abstract",
    "Experimental comparison is described qualitatively; details of the referenced experiments are not provided in the abstract"
  ],
  "evidence_strength": "low",
  "confidence": 0.74,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "ephaptic transmission",
    "extracellular electric field",
    "CA3 pyramidal cells",
    "two-compartment model",
    "DC electric field",
    "sinusoidal electric field",
    "neuronal excitability",
    "bifurcation analysis",
    "subthreshold response"
  ],
  "suggested_hubs": [
    {
      "slug": "other",
      "weight": 0.2,
      "reason": "Neuroscience modeling of extracellular electric field effects; not clearly tied to specific EMF sources (e.g., mobile/Wi‑Fi/5G) or policy hubs."
    }
  ]
}

AI can be wrong. Always verify against the paper.

AI-extracted fields are generated from the abstract and metadata and may be incomplete or incorrect. This material is for informational purposes and is not medical advice.

Identifiers and source

DOI: 10.1007/s11571-013-9269-6
PubMed: 24808928

Read the original paper →

Related papers

← Back to the Research Library