Related Experiment Video
Updated: Aug 14, 2026
Multi-electrode Array Recordings of Human Epileptic Postoperative Cortical Tissue
Published on: October 26, 2014
Carbamazepine effects on Na+ currents in human dentate granule cells from epileptogenic tissue
G Reckziegel1, H Beck, J Schramm
1Department of Epileptology, University of Bonn Medical Center, Germany.
Purpose:
Carbamazepine (CBZ) is a well-established drug in the therapy of temporal lobe epilepsy (TLE). The anticonvulsant action of CBZ has been explained mainly by use-dependent effects on voltage-dependent Na+ channels in various nonhuman cell type. However, it is unclear whether Na+ currents in neurons within the focal epileptogenic area of patients with medically intractable TLE show similar characteristics.
Methods:
Therefore we used the whole-cell patch-clamp technique to investigate the effects of CBZ on voltage-dependent Na+ currents in 23 acutely isolated dentate granule cells (DGCs) from the resected hippocampus of eight patients with medically intractable TLE.
Results:
As in findings in animal preparations, CBZ significantly reduced the amplitude of the Na+ current and significantly shifted the current-voltage dependence of the steady-state inactivation in the hyperpolarizing direction. In contrast, the rapid component of the recovery from inactivation of the Na+ currents was not affected by CBZ. In addition, the reduction of the Na+ current amplitude observed during repetitive stimulation with depolarizing pulses was not significantly altered by CBZ.
Conclusions:
In summary, CBZ strongly affects the voltage-dependent steady-state inactivation, with no effects on the removal of inactivation in Na+ currents of human DGCs. In spite of the lack of suitable control material, the CBZ insensitivity of the removal of inactivation may be an interesting concept to explain the medically intractable TLE in these patients.
Insights
Carbamazepine (CBZ) affects sodium channel inactivation in human epilepsy neurons, but not recovery from inactivation. This may explain why some temporal lobe epilepsy (TLE) cases are medically intractable.
Area of Science:
- Neuroscience
- Pharmacology
- Epilepsy Research
Background:
- Carbamazepine (CBZ) is a standard treatment for temporal lobe epilepsy (TLE).
- CBZ's anticonvulsant effects are linked to voltage-dependent sodium (Na+) channels.
- Its action on human neurons in focal epilepsy remains unclear.
Purpose of the Study:
- Investigate CBZ's effects on Na+ currents in human TLE neurons.
- Determine if human TLE neurons respond similarly to nonhuman models.
Main Methods:
- Whole-cell patch-clamp technique.
- Studied acutely isolated dentate granule cells (DGCs) from TLE patients.
- Examined effects of CBZ on voltage-dependent Na+ currents.
Main Results:
- CBZ reduced Na+ current amplitude and shifted steady-state inactivation hyperpolarizing.
- CBZ did not affect the rapid component of Na+ current recovery from inactivation.
- Repetitive stimulation effects on Na+ current amplitude were not significantly altered by CBZ.
Conclusions:
- CBZ significantly impacts steady-state inactivation of human DGC Na+ currents.
- CBZ does not affect the removal of inactivation in these neurons.
- CBZ insensitivity in Na+ current recovery may explain medically intractable TLE.
Related Concept Videos
01:24Epilepsy and Seizures: Overview
Various factors can trigger epilepsy, including genetic factors, brain damage, metabolic causes, and unknown etiology. Diagnosis of epilepsy involves electroencephalography (EEG), which...
01:20Antiepileptic Drugs: Modulators of Neurotransmitter Release Mediated by SV2A Protein
SV2A is a transmembrane glycoprotein located predominantly in the brain, modulating the release of neurotransmitters for neuronal communication. Both levetiracetam and brivaracetam exhibit a high affinity for...