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Pathophysiology Nodes

5
5 shared nodes are defined in this module.
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Cell Types

2
Neuron CL:0000540 Cell Ontology (CL) Relation: this mechanism module involves this cell type This mechanism module involves Neuron (CL:0000540). CL:0000540 is a cell type from the Cell Ontology. GABAergic Neuron CL:0000617 Cell Ontology (CL) Relation: this mechanism module involves this cell type This mechanism module involves GABAergic Neuron (CL:0000617). CL:0000617 is a cell type from the Cell Ontology.
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Biological Processes

4
Regulation of Membrane Potential GO:0042391 ⚠ ABNORMAL Gene Ontology (GO) Relation: this mechanism module involves this biological process This mechanism module involves abnormal Regulation of Membrane Potential (GO:0042391). GO:0042391 is a biological process from the Gene Ontology. Chemical Synaptic Transmission GO:0007268 ⚠ ABNORMAL Gene Ontology (GO) Relation: this mechanism module involves this biological process This mechanism module involves abnormal Chemical Synaptic Transmission (GO:0007268). GO:0007268 is a biological process from the Gene Ontology. GABA Signaling Pathway GO:0007214 ↓ DECREASED Gene Ontology (GO) Relation: this mechanism module involves this biological process This mechanism module involves decreased GABA Signaling Pathway (GO:0007214). GO:0007214 is a biological process from the Gene Ontology. Action Potential GO:0001508 ↑ INCREASED Gene Ontology (GO) Relation: this mechanism module involves this biological process This mechanism module involves increased Action Potential (GO:0001508). GO:0001508 is a biological process from the Gene Ontology.
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Notes

This is a mechanism module, not a specific disease. Disorder entries reference individual nodes via conforms_to (e.g., "epilepsy_excitation_inhibition_imbalance#Neuronal Hyperexcitability and Hypersynchrony"). Conforming nodes should substitute the disorder-specific driver of E/I imbalance: sodium/potassium/calcium channel variants in genetic channelopathies, GABAergic interneuron dysfunction, mTOR-pathway cortical malformations, or acquired network reorganization after injury. The E/I-balance framework is a useful paradigm but is acknowledged in the literature to be an incomplete account of all epilepsy mechanisms.
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Module Collections

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Used By Disorder Entries

94
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Pathograph

Use the checkboxes to hide or show graph categories. Hover nodes for evidence-backed metadata.
Pathograph: causal mechanism network for Epilepsy Excitation-Inhibition Imbalance Module Interactive directed graph showing how this shared module's pathophysiology nodes connect.
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Pathophysiology

5
Ion Channel and Synaptic Dysfunction
trigger
The conserved initiating lesion is an abnormality of neuronal ion channels or synaptic transmission that alters the intrinsic and synaptic excitability of neurons. This encompasses voltage-gated channel variants, neurotransmitter receptor defects, and synaptic-protein abnormalities across genetic and acquired epilepsies.
Neuron CL:0000540 Cell Ontology (CL) Relation: this pathophysiological event involves this cell type This pathophysiological event involves Neuron (CL:0000540). CL:0000540 is a cell type from the Cell Ontology.
Regulation of Membrane Potential GO:0042391 ⚠ ABNORMAL Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves abnormal Regulation of Membrane Potential (GO:0042391). GO:0042391 is a biological process from the Gene Ontology. Chemical Synaptic Transmission GO:0007268 ⚠ ABNORMAL Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves abnormal Chemical Synaptic Transmission (GO:0007268). GO:0007268 is a biological process from the Gene Ontology.
Show evidence (1 reference)
PMID:30764523 SUPPORT Other
"Mechanisms underlying seizures and epilepsy have traditionally been considered to involve abnormalities of ion channels or synaptic function."
Establishes ion-channel and synaptic abnormalities as the conserved initiating lesion underlying seizures and epilepsy. Evidence source is OTHER because this is a review article.
Excitation-Inhibition Imbalance
amplifier
Channel and synaptic dysfunction shift the balance between excitatory (glutamatergic) and inhibitory (GABAergic) signaling toward net excitation, through increased excitation, decreased inhibition, or both. Loss of GABAergic inhibitory tone is a recurrent contributor across epilepsy syndromes.
GABAergic Neuron CL:0000617 Cell Ontology (CL) Relation: this pathophysiological event involves this cell type This pathophysiological event involves GABAergic Neuron (CL:0000617). CL:0000617 is a cell type from the Cell Ontology.
GABA Signaling Pathway GO:0007214 ↓ DECREASED Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves decreased GABA Signaling Pathway, annotated with gamma-aminobutyric acid signaling pathway (GO:0007214). GO:0007214 is a biological process from the Gene Ontology.
Show evidence (2 references)
PMID:30764523 SUPPORT Other
"Those considerations gave rise to the excitation/inhibition (E/I) imbalance theory, whereby increased excitation, decreased inhibition, or both favor a hyperexcitable state and an increased propensity for seizure generation and epileptogenesis."
Directly defines the E/I imbalance paradigm in which increased excitation and/or decreased inhibition favor hyperexcitability, the conserved amplifier step. Evidence source is OTHER because this is a review article.
PMID:33808762 SUPPORT Other
"In the brain, GABA is a major inhibitory neurotransmitter and plays a pivotal role in maintaining E/I balance."
Establishes GABAergic signaling as the principal inhibitory arm whose loss contributes to E/I imbalance in epilepsy. Evidence source is OTHER because this is a review article.
Neuronal Hyperexcitability and Hypersynchrony
central effector
Net excitatory bias produces a hyperexcitable neuronal state in which populations of neurons fire excessively and synchronously. This hypersynchrony is the central effector that converts altered excitability into paroxysmal network discharges.
neuron CL:0000540 Cell Ontology (CL) Relation: this pathophysiological event involves this cell type This pathophysiological event involves neuron (CL:0000540). CL:0000540 is a cell type from the Cell Ontology.
Action Potential GO:0001508 ↑ INCREASED Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves increased Action Potential (GO:0001508). GO:0001508 is a biological process from the Gene Ontology.
Show evidence (1 reference)
PMID:17618543 SUPPORT Other
"genes, developmental mechanisms, and neuronal plasticity play major roles in creating a state of underlying hyperexcitability."
Describes the convergence of multiple mechanisms on a state of underlying hyperexcitability, the central effector of this module. Evidence source is OTHER because this is a review article.
Seizure Generation and Epileptogenesis
effector
Hypersynchronous discharges manifest as seizures. Over time, seizure-related and lesion-related processes drive epileptogenesis — network reorganization that lowers seizure threshold and renders the brain chronically prone to spontaneous seizures.
neuron CL:0000540 Cell Ontology (CL) Relation: this pathophysiological event involves this cell type This pathophysiological event involves neuron (CL:0000540). CL:0000540 is a cell type from the Cell Ontology.
Show evidence (1 reference)
PMID:30764523 SUPPORT Other
"increased excitation, decreased inhibition, or both favor a hyperexcitable state and an increased propensity for seizure generation and epileptogenesis."
Links the hyperexcitable state to seizure generation and epileptogenesis, the effector step of this module. Evidence source is OTHER because this is a review article.
Recurrent Unprovoked Seizures
consequence
The clinical endpoint is the state of recurrent, unprovoked seizures that defines epilepsy. Seizures may continue to evolve over the lifespan as the underlying network continues to reorganize.
neuron CL:0000540 Cell Ontology (CL) Relation: this pathophysiological event involves this cell type This pathophysiological event involves neuron (CL:0000540). CL:0000540 is a cell type from the Cell Ontology.
Show evidence (1 reference)
PMID:17618543 SUPPORT Other
"the state of recurrent unprovoked seizures that defines epilepsy itself."
Directly identifies recurrent unprovoked seizures as the defining clinical consequence of this module. Evidence source is OTHER because this is a review article.