Component
Whether a GABA-A response hyperpolarises or depolarises the cell
Whether a GABA-A response hyperpolarises or depolarises the cell. Species, exposure and limitations are retained in each linked claim.
4 recorded relationships. Experimental role, claim status and evidence remain attached to each record.
How nutrients influence it
Every nutrient with a recorded effect on this component, credited to the nutrient that acted rather than the chapter that recorded it. Open a nutrient to see the findings and the conditions they were measured under.
Other things that act on it
Enzymes, hormones, genes, and other components with a recorded effect. These are not nutrients, so they do not count toward the arrows above. Each finding names the chapter that recorded it.
How nutrients reach it in more than one step
Chains of two or more recorded steps that end here, grouped by the nutrient they start from. Each step is a separate finding, so a chain is a route a mechanism could take, not proof that it does.
Tracing routes…
What it does
Every recorded relationship this component is part of, grouped by its role. Plain wording comes first; the technical statement follows.
What acts on it
GABA is the main inhibitory transmitter in the adult brain and exerts its fast hyperpolarizing effect through activation of anion-permeant GABA-A receptors, however during early neuronal development GABA-A-receptor-mediated responses are often depolarizing, in pyramidal neurons of the rat hippocampus the ontogenetic change in GABA-A-mediated responses from depolarizing to hyperpolarizing is coupled to a developmental induction of the expression of the neuronal chloride-extruding potassium-chloride co-transporter KCC2, and antisense oligonucleotide inhibition of KCC2 expression produces a marked positive shift in the reversal potential of GABA-A responses in functionally mature hippocampal pyramidal neurons.
Experimental context and source evidence
- availability_state
- machinery_impairment Imported condition classification; unverified.
- evidence_span
- {"source_cache": "artifacts/gaba-research/9930699.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "2ef63b1f73a7a33ae3fc709c3ace45a585604d86f9fe1bce8c83405d21cdcaa6", "start_char": 0, "end_char": 1181, "text_sha256": "2ef63b1f73a7a33ae3fc709c3ace45a585604d86f9fe1bce8c83405d21cdcaa6"}
- experimental_model
- Developmental comparison of GABA-A responses with antisense inhibition of the transporter
- exposure
- Antisense oligonucleotide inhibition of KCC2 expression in functionally mature neurons
- limitations
- Rat hippocampal neurons. It establishes which transporter sets the gradient; it does not address other cell types.
- nutrient_topic
- GABA research collection; topical membership is not evidence of a direct clinical effect, and the sign of a GABA response depends on the chloride gradient of the cell it was measured in. · Gamma-aminobutyric acid
- organism
- Rat
- plain_language
- The same receptor flips from exciting to inhibiting as the cell learns to pump chloride out, and knocking the pump down flips it back.
- primary_references
- [gb-p9930699] The K+/Cl- co-transporter KCC2 renders GABA hyperpolarizing during neuronal maturation. (1999). https://pubmed.ncbi.nlm.nih.gov/9930699/ DOI: 10.1038/16697
- tissue_or_cell_type
- Hippocampal pyramidal neuron
- trigger_kind
- machinery_impairment Imported condition classification; unverified.
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Developmental comparison of GABA-A responses with antisense inhibition of the transporter · source_derived_draft · unverified_draft
### gb-the-transporter-sets-the-sign GABA is the main inhibitory transmitter in the adult brain and exerts its fast hyperpolarizing effect through activation of anion-permeant GABA-A receptors, however during early neuronal development GABA-A-receptor-mediated responses are often depolarizing, in pyramidal neurons of the rat hippocampus the ontogenetic change in GABA-A-mediated responses from depolarizing to hyperpolarizing is coupled to a developmental induction of the expression of the neuronal chloride-extruding potassium-chloride co-transporter KCC2, and antisense oligonucleotide inhibition of KCC2 expression produces a marked positive shift in the reversal potential of GABA-A responses in functionally mature hippocampal pyramidal neurons. Condition category: machinery_impairment nutrient_topic: GABA research collection; topical membership is not evidence of a direct clinical effect, and the sign of a GABA response depends on the chloride gradient of the cell it was measured in. plain_language: The same receptor flips from exciting to inhibiting as the cell learns to pump chloride out, and knocking the pump down flips it back. organism: Rat tissue_or_cell_type: Hippocampal pyramidal neuron experimental_model: Developmental comparison of GABA-A responses with antisense inhibition of the transporter limitations: Rat hippocampal neurons. It establishes which transporter sets the gradient; it does not address other cell types. exposure: Antisense oligonucleotide inhibition of KCC2 expression in functionally mature neurons evidence_span: {"source_cache": "artifacts/gaba-research/9930699.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "2ef63b1f73a7a33ae3fc709c3ace45a585604d86f9fe1bce8c83405d21cdcaa6", "start_char": 0, "end_char": 1181, "text_sha256": "2ef63b1f73a7a33ae3fc709c3ace45a585604d86f9fe1bce8c83405d21cdcaa6"} [gb-p9930699] The K+/Cl- co-transporter KCC2 renders GABA hyperpolarizing during neuronal maturation. (1999). https://pubmed.ncbi.nlm.nih.gov/9930699/ DOI: 10.1038/16697
Complete structured claim and evidence
Where it participates (unsigned role)
Unlike in adult brain or islet alpha-cells in which GABA exerts hyperpolarizing effects, in islet beta-cells GABA produces membrane depolarization and calcium influx leading to the activation of PI3-kinase and Akt-dependent growth and survival pathways, this provides a potential mechanism underlying findings that GABA therapy preserves beta-cell mass and prevents the development of type 1 diabetes, remarkably in severely diabetic mice GABA restores beta-cell mass and reverses the disease, and GABA suppresses insulitis and systemic inflammatory cytokine production.
Experimental context and source evidence
- evidence_span
- {"source_cache": "artifacts/gaba-research/21709230.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "926bc916592c55cf6089bcb240ec5545e0ff3850e6d927bb82efacfc61841175", "start_char": 0, "end_char": 1117, "text_sha256": "926bc916592c55cf6089bcb240ec5545e0ff3850e6d927bb82efacfc61841175"}
- experimental_model
- Islet cell electrophysiology and signalling with GABA therapy in diabetes-prone and severely diabetic mice
- exposure
- GABA given therapeutically, with membrane potential, calcium influx and survival pathway readouts in beta cells
- limitations
- A mouse therapy study. Its electrophysiological claim about beta cells is stated as a contrast with alpha cells and brain rather than shown alongside a measured chloride gradient.
- nutrient_topic
- GABA research collection; topical membership is not evidence of a direct clinical effect, and the sign of a GABA response depends on the chloride gradient of the cell it was measured in. · Gamma-aminobutyric acid
- organism
- Mouse
- plain_language
- In the insulin-producing cell the same molecule does the opposite of what it does in the brain, and the cells survive better for it.
- primary_references
- [gb-p21709230] GABA exerts protective and regenerative effects on islet beta cells and reverses diabetes. (2011). https://pubmed.ncbi.nlm.nih.gov/21709230/ DOI: 10.1073/pnas.1102715108
- tissue_or_cell_type
- Pancreatic islet and immune system
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Islet cell electrophysiology and signalling with GABA therapy in diabetes-prone and severely diabetic mice · source_derived_draft · unverified_draft
### gb-gaba-depolarises-the-beta-cell Unlike in adult brain or islet alpha-cells in which GABA exerts hyperpolarizing effects, in islet beta-cells GABA produces membrane depolarization and calcium influx leading to the activation of PI3-kinase and Akt-dependent growth and survival pathways, this provides a potential mechanism underlying findings that GABA therapy preserves beta-cell mass and prevents the development of type 1 diabetes, remarkably in severely diabetic mice GABA restores beta-cell mass and reverses the disease, and GABA suppresses insulitis and systemic inflammatory cytokine production. Condition category: normal nutrient_topic: GABA research collection; topical membership is not evidence of a direct clinical effect, and the sign of a GABA response depends on the chloride gradient of the cell it was measured in. plain_language: In the insulin-producing cell the same molecule does the opposite of what it does in the brain, and the cells survive better for it. organism: Mouse tissue_or_cell_type: Pancreatic islet and immune system experimental_model: Islet cell electrophysiology and signalling with GABA therapy in diabetes-prone and severely diabetic mice limitations: A mouse therapy study. Its electrophysiological claim about beta cells is stated as a contrast with alpha cells and brain rather than shown alongside a measured chloride gradient. exposure: GABA given therapeutically, with membrane potential, calcium influx and survival pathway readouts in beta cells evidence_span: {"source_cache": "artifacts/gaba-research/21709230.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "926bc916592c55cf6089bcb240ec5545e0ff3850e6d927bb82efacfc61841175", "start_char": 0, "end_char": 1117, "text_sha256": "926bc916592c55cf6089bcb240ec5545e0ff3850e6d927bb82efacfc61841175"} [gb-p21709230] GABA exerts protective and regenerative effects on islet beta cells and reverses diabetes. (2011). https://pubmed.ncbi.nlm.nih.gov/21709230/ DOI: 10.1073/pnas.1102715108
Complete structured claim and evidenceFollowing peripheral nerve injury there is a trans-synaptic reduction in the expression of the potassium-chloride exporter KCC2 and consequent disruption of anion homeostasis in neurons of lamina I of the superficial dorsal horn, the resulting shift in the transmembrane anion gradient caused normally inhibitory anionic synaptic currents to be excitatory, substantially driving up the net excitability of lamina I neurons, and local blockade or knock-down of the spinal KCC2 exporter in intact rats markedly reduced the nociceptive threshold, confirming that the disruption of anion homeostasis was sufficient to cause neuropathic pain.
Experimental context and source evidence
- availability_state
- machinery_impairment Imported condition classification; unverified.
- evidence_span
- {"source_cache": "artifacts/gaba-research/12931188.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "f465ce014f8ada8e6018e23f0009197609a343241b8d0926b34ed186ce345fa4", "start_char": 0, "end_char": 1073, "text_sha256": "f465ce014f8ada8e6018e23f0009197609a343241b8d0926b34ed186ce345fa4"}
- experimental_model
- Recordings from lamina I neurons after peripheral nerve injury, with spinal blockade and knockdown in intact animals
- exposure
- Peripheral nerve injury, and local blockade or knock-down of spinal KCC2 in intact rats
- limitations
- The knockdown in intact animals is what makes this causal rather than correlative: reproducing the gradient change alone reproduced the pain phenotype.
- nutrient_topic
- GABA research collection; topical membership is not evidence of a direct clinical effect, and the sign of a GABA response depends on the chloride gradient of the cell it was measured in. · Gamma-aminobutyric acid
- organism
- Rat
- plain_language
- After nerve injury the inhibitory synapses in the pain pathway start doing the opposite of inhibiting.
- primary_references
- [gb-p12931188] Trans-synaptic shift in anion gradient in spinal lamina I neurons as a mechanism of neuropathic pain. (2003). https://pubmed.ncbi.nlm.nih.gov/12931188/ DOI: 10.1038/nature01868
- tissue_or_cell_type
- Spinal lamina I dorsal horn neuron
- trigger_kind
- machinery_impairment Imported condition classification; unverified.
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Recordings from lamina I neurons after peripheral nerve injury, with spinal blockade and knockdown in intact animals · source_derived_draft · unverified_draft
### gb-inhibition-becomes-excitation Following peripheral nerve injury there is a trans-synaptic reduction in the expression of the potassium-chloride exporter KCC2 and consequent disruption of anion homeostasis in neurons of lamina I of the superficial dorsal horn, the resulting shift in the transmembrane anion gradient caused normally inhibitory anionic synaptic currents to be excitatory, substantially driving up the net excitability of lamina I neurons, and local blockade or knock-down of the spinal KCC2 exporter in intact rats markedly reduced the nociceptive threshold, confirming that the disruption of anion homeostasis was sufficient to cause neuropathic pain. Condition category: machinery_impairment nutrient_topic: GABA research collection; topical membership is not evidence of a direct clinical effect, and the sign of a GABA response depends on the chloride gradient of the cell it was measured in. plain_language: After nerve injury the inhibitory synapses in the pain pathway start doing the opposite of inhibiting. organism: Rat tissue_or_cell_type: Spinal lamina I dorsal horn neuron experimental_model: Recordings from lamina I neurons after peripheral nerve injury, with spinal blockade and knockdown in intact animals limitations: The knockdown in intact animals is what makes this causal rather than correlative: reproducing the gradient change alone reproduced the pain phenotype. exposure: Peripheral nerve injury, and local blockade or knock-down of spinal KCC2 in intact rats evidence_span: {"source_cache": "artifacts/gaba-research/12931188.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "f465ce014f8ada8e6018e23f0009197609a343241b8d0926b34ed186ce345fa4", "start_char": 0, "end_char": 1073, "text_sha256": "f465ce014f8ada8e6018e23f0009197609a343241b8d0926b34ed186ce345fa4"} [gb-p12931188] Trans-synaptic shift in anion gradient in spinal lamina I neurons as a mechanism of neuropathic pain. (2003). https://pubmed.ncbi.nlm.nih.gov/12931188/ DOI: 10.1038/nature01868
Complete structured claim and evidenceATP-stimulated microglia cause a depolarizing shift in the anion reversal potential in spinal lamina I neurons which inverts the polarity of currents activated by GABA as occurs after peripheral nerve injury, applying brain-derived neurotrophic factor mimics the alteration, blocking signalling between BDNF and the receptor TrkB reverses the allodynia and the shift that follows both nerve injury and administration of ATP-stimulated microglia, and preventing BDNF release from microglia by pretreating them with interfering RNA before ATP stimulation also inhibits the effects on the withdrawal threshold.
Experimental context and source evidence
- availability_state
- machinery_impairment Imported condition classification; unverified.
- evidence_span
- {"source_cache": "artifacts/gaba-research/16355225.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "75e8e0a216ad3cbd68087f650d263b38fe34b73a6b3b253b929b2af26434e001", "start_char": 0, "end_char": 1571, "text_sha256": "75e8e0a216ad3cbd68087f650d263b38fe34b73a6b3b253b929b2af26434e001"}
- experimental_model
- Recordings from lamina I neurons exposed to ATP-stimulated microglia, with BDNF blockade and interfering RNA
- exposure
- ATP-stimulated microglia, applied BDNF, BDNF-TrkB blockade, and interfering RNA against BDNF in microglia
- limitations
- Each link in the chain is cut separately, which is what makes the assignment to BDNF strong. It remains a rodent model of one pain state.
- nutrient_topic
- GABA research collection; topical membership is not evidence of a direct clinical effect, and the sign of a GABA response depends on the chloride gradient of the cell it was measured in. · Gamma-aminobutyric acid
- organism
- Rat
- plain_language
- An immune cell in the spinal cord releases a growth factor that turns the brake into an accelerator.
- primary_references
- [gb-p16355225] BDNF from microglia causes the shift in neuronal anion gradient underlying neuropathic pain. (2005). https://pubmed.ncbi.nlm.nih.gov/16355225/ DOI: 10.1038/nature04223
- tissue_or_cell_type
- Spinal lamina I dorsal horn neuron and microglia
- trigger_kind
- machinery_impairment Imported condition classification; unverified.
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Recordings from lamina I neurons exposed to ATP-stimulated microglia, with BDNF blockade and interfering RNA · source_derived_draft · unverified_draft
### gb-microglia-invert-the-current ATP-stimulated microglia cause a depolarizing shift in the anion reversal potential in spinal lamina I neurons which inverts the polarity of currents activated by GABA as occurs after peripheral nerve injury, applying brain-derived neurotrophic factor mimics the alteration, blocking signalling between BDNF and the receptor TrkB reverses the allodynia and the shift that follows both nerve injury and administration of ATP-stimulated microglia, and preventing BDNF release from microglia by pretreating them with interfering RNA before ATP stimulation also inhibits the effects on the withdrawal threshold. Condition category: machinery_impairment nutrient_topic: GABA research collection; topical membership is not evidence of a direct clinical effect, and the sign of a GABA response depends on the chloride gradient of the cell it was measured in. plain_language: An immune cell in the spinal cord releases a growth factor that turns the brake into an accelerator. organism: Rat tissue_or_cell_type: Spinal lamina I dorsal horn neuron and microglia experimental_model: Recordings from lamina I neurons exposed to ATP-stimulated microglia, with BDNF blockade and interfering RNA limitations: Each link in the chain is cut separately, which is what makes the assignment to BDNF strong. It remains a rodent model of one pain state. exposure: ATP-stimulated microglia, applied BDNF, BDNF-TrkB blockade, and interfering RNA against BDNF in microglia evidence_span: {"source_cache": "artifacts/gaba-research/16355225.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "75e8e0a216ad3cbd68087f650d263b38fe34b73a6b3b253b929b2af26434e001", "start_char": 0, "end_char": 1571, "text_sha256": "75e8e0a216ad3cbd68087f650d263b38fe34b73a6b3b253b929b2af26434e001"} [gb-p16355225] BDNF from microglia causes the shift in neuronal anion gradient underlying neuropathic pain. (2005). https://pubmed.ncbi.nlm.nih.gov/16355225/ DOI: 10.1038/nature04223
Complete structured claim and evidence
The events it takes part in
A mechanism often involves more than two components. These are the full events, with every participant and its role.
Situations it appears in
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In the sources
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Open hypotheses
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