Component

Rat NMDA-type glutamate receptors, subunits unresolved

Rat NMDA-type glutamate receptors, subunits unresolved. Species, exposure and limitations are retained in each linked claim.

7 recorded relationships. Experimental role, claim status and evidence remain attached to each record.

Read recorded mechanisms Open recursive mind map

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.

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.

Recorded relationships

What acts on it

  1. Extracellular agmatine blocked NMDA currents in rat hippocampal neurons in a voltage- and concentration-dependent manner; estimated pore-site Kd was 952 micromolar at 0 mV.

    Agmatine → Rat NMDA-type glutamate receptors, subunits unresolved source_derived_draftungraded
    Experimental context and source evidence
    evidence_access
    Primary abstract
    experimental_model
    Cultured rat hippocampal neurons; whole-cell patch clamp.
    limitations
    The inferred pore site is not a solved binding structure or measured oral human brain exposure.
    nutrient_topic
    Agmatine Sulfate collection; species, compartment, exposure, co-substrates and manipulation remain explicit. · Agmatine Sulfate
    plain_language
    Its glutamate-receptor effect depends on electrical conditions and concentration.
    primary_references
    Agmatine selectively blocks the N-methyl-D-aspartate subclass of glutamate receptor channels in rat hippocampal neurons. · 1999 · https://pubmed.ncbi.nlm.nih.gov/9918557/

    Agmatine Sulfate: transport, guanidino metabolism, ion channels and cross-nutrient mechanisms (2026-09-20) · lines 260–266

    AI-assisted research curation; primary references, access levels and experimental limitations individually identified. Not publisher full text. · supports · Cultured rat hippocampal neurons; whole-cell patch clamp. · source_derived_draft · unverified_draft

    ## agmatine-sulfate-nmda-block Its glutamate-receptor effect depends on electrical conditions and concentration. Extracellular agmatine blocked NMDA currents in rat hippocampal neurons in a voltage- and concentration-dependent manner; estimated pore-site Kd was 952 micromolar at 0 mV. Model: Cultured rat hippocampal neurons; whole-cell patch clamp. Limitations: The inferred pore site is not a solved binding structure or measured oral human brain exposure. Evidence access: Primary abstract Agmatine selectively blocks the N-methyl-D-aspartate subclass of glutamate receptor channels in rat hippocampal neurons. · 1999 · https://pubmed.ncbi.nlm.nih.gov/9918557/
    Complete structured claim and evidence

  2. Putrescine had little NMDA-blocking effect compared with agmatine or arcaine in the same experiments.

    Putrescine → Rat NMDA-type glutamate receptors, subunits unresolved source_derived_draftungraded
    Experimental context and source evidence
    evidence_access
    Primary abstract
    experimental_model
    Rat neuron comparison of guanidine-containing and diamine compounds.
    limitations
    The result supports structural specificity; it does not measure metabolic conversion during recording.
    nutrient_topic
    Agmatine Sulfate collection; species, compartment, exposure, co-substrates and manipulation remain explicit. · Agmatine Sulfate
    plain_language
    Converting agmatine to a related amine can change channel activity.
    primary_references
    Agmatine selectively blocks the N-methyl-D-aspartate subclass of glutamate receptor channels in rat hippocampal neurons. · 1999 · https://pubmed.ncbi.nlm.nih.gov/9918557/

    Agmatine Sulfate: transport, guanidino metabolism, ion channels and cross-nutrient mechanisms (2026-09-20) · lines 276–282

    AI-assisted research curation; primary references, access levels and experimental limitations individually identified. Not publisher full text. · supports · Rat neuron comparison of guanidine-containing and diamine compounds. · source_derived_draft · unverified_draft

    ## agmatine-sulfate-putrescine-nmda Converting agmatine to a related amine can change channel activity. Putrescine had little NMDA-blocking effect compared with agmatine or arcaine in the same experiments. Model: Rat neuron comparison of guanidine-containing and diamine compounds. Limitations: The result supports structural specificity; it does not measure metabolic conversion during recording. Evidence access: Primary abstract Agmatine selectively blocks the N-methyl-D-aspartate subclass of glutamate receptor channels in rat hippocampal neurons. · 1999 · https://pubmed.ncbi.nlm.nih.gov/9918557/
    Complete structured claim and evidence

  3. Spermine still potentiated NMDA current in the presence of agmatine, supporting distinct interaction sites for the two compounds.

    Spermine → Rat NMDA-type glutamate receptors, subunits unresolved source_derived_draftungraded
    Experimental context and source evidence
    evidence_access
    Primary abstract
    experimental_model
    Rat hippocampal-neuron electrophysiology.
    limitations
    This is a cellular interaction, not evidence that co-supplementation is beneficial.
    nutrient_topic
    Agmatine Sulfate collection; species, compartment, exposure, co-substrates and manipulation remain explicit. · Agmatine Sulfate
    plain_language
    Two connected polyamine-related molecules can push the same channel in different directions.
    primary_references
    Agmatine selectively blocks the N-methyl-D-aspartate subclass of glutamate receptor channels in rat hippocampal neurons. · 1999 · https://pubmed.ncbi.nlm.nih.gov/9918557/

    Agmatine Sulfate: transport, guanidino metabolism, ion channels and cross-nutrient mechanisms (2026-09-20) · lines 268–274

    AI-assisted research curation; primary references, access levels and experimental limitations individually identified. Not publisher full text. · supports · Rat hippocampal-neuron electrophysiology. · source_derived_draft · unverified_draft

    ## agmatine-sulfate-spermine-nmda Two connected polyamine-related molecules can push the same channel in different directions. Spermine still potentiated NMDA current in the presence of agmatine, supporting distinct interaction sites for the two compounds. Model: Rat hippocampal-neuron electrophysiology. Limitations: This is a cellular interaction, not evidence that co-supplementation is beneficial. Evidence access: Primary abstract Agmatine selectively blocks the N-methyl-D-aspartate subclass of glutamate receptor channels in rat hippocampal neurons. · 1999 · https://pubmed.ncbi.nlm.nih.gov/9918557/
    Complete structured claim and evidence

  4. Kynurenic-acid NMDA-blocking IC50 shifted from about 15 to 235 micromolar when 10 micromolar glycine was present.

    Glycine → Rat NMDA-type glutamate receptors, subunits unresolved source_derived_draftungraded
    Experimental context and source evidence
    evidence_access
    Primary abstract
    experimental_model
    Rat neuronal electrophysiological assay.
    limitations
    An assay co-agonist effect does not show that glycine supplements change human disease outcomes.
    nutrient_topic
    Tryptophan collection; molecular form, preparation, species, exposure and manipulation remain explicit. · L-Tryptophan
    plain_language
    A second amino acid changed how strongly the metabolite blocked a receptor.
    primary_references
    The brain metabolite kynurenic acid inhibits alpha7 nicotinic receptor activity and increases non-alpha7 nicotinic receptor expression: physiopathological implications. · 2001 · https://pubmed.ncbi.nlm.nih.gov/11567036/ · DOI 10.1523/JNEUROSCI.21-19-07463.2001

    Tryptophan: transport, protein synthesis, neuroactive metabolites, NAD and microbial pathways (2026-09-19) · lines 314–320

    AI-assisted research curation; primary-abstract references and experimental limitations individually identified. Not publisher full text. · supports · Rat neuronal electrophysiological assay. · source_derived_draft · unverified_draft

    ## tryptophan-glycine-kyna-nmda A second amino acid changed how strongly the metabolite blocked a receptor. Kynurenic-acid NMDA-blocking IC50 shifted from about 15 to 235 micromolar when 10 micromolar glycine was present. Model: Rat neuronal electrophysiological assay. Limitations: An assay co-agonist effect does not show that glycine supplements change human disease outcomes. Evidence access: Primary abstract The brain metabolite kynurenic acid inhibits alpha7 nicotinic receptor activity and increases non-alpha7 nicotinic receptor expression: physiopathological implications. · 2001 · https://pubmed.ncbi.nlm.nih.gov/11567036/ · DOI 10.1523/JNEUROSCI.21-19-07463.2001
    Complete structured claim and evidence

  5. Adding 30 micromolar magnesium reduced quinolinate-activated NMDA channel mean open time to about one-third at minus 100 mV.

    Mg2+ → Rat NMDA-type glutamate receptors, subunits unresolved source_derived_draftungraded
    Experimental context and source evidence
    evidence_access
    Primary abstract
    experimental_model
    Rat hippocampal patch-clamp experiment.
    limitations
    Does not establish that oral magnesium prevents quinolinate-related disease.
    nutrient_topic
    Tryptophan collection; molecular form, preparation, species, exposure and manipulation remain explicit. · L-Tryptophan
    plain_language
    Magnesium and membrane voltage changed the receptor response.
    primary_references
    Quinolinate activation of N-methyl-D-aspartate ion channels in rat hippocampal neurons. · 1990 · https://pubmed.ncbi.nlm.nih.gov/1700844/ · DOI 10.1016/0304-3940(90)90098-t

    Tryptophan: transport, protein synthesis, neuroactive metabolites, NAD and microbial pathways (2026-09-19) · lines 282–288

    AI-assisted research curation; primary-abstract references and experimental limitations individually identified. Not publisher full text. · supports · Rat hippocampal patch-clamp experiment. · source_derived_draft · unverified_draft

    ## tryptophan-magnesium-nmda Magnesium and membrane voltage changed the receptor response. Adding 30 micromolar magnesium reduced quinolinate-activated NMDA channel mean open time to about one-third at minus 100 mV. Model: Rat hippocampal patch-clamp experiment. Limitations: Does not establish that oral magnesium prevents quinolinate-related disease. Evidence access: Primary abstract Quinolinate activation of N-methyl-D-aspartate ion channels in rat hippocampal neurons. · 1990 · https://pubmed.ncbi.nlm.nih.gov/1700844/ · DOI 10.1016/0304-3940(90)90098-t
    Complete structured claim and evidence

  6. Quinolinate at 75 micromolar opened NMDA channels in cultured rat hippocampal neurons in calcium-containing, magnesium-free recording solution.

    Quinolinic acid → Rat NMDA-type glutamate receptors, subunits unresolved source_derived_draftungraded
    Experimental context and source evidence
    evidence_access
    Primary abstract
    experimental_model
    Rat CA1 neuronal single-channel recording; 1.8 mM calcium.
    limitations
    Quinolinate is not tryptophan itself; bath concentration is not a dietary dose.
    nutrient_topic
    Tryptophan collection; molecular form, preparation, species, exposure and manipulation remain explicit. · L-Tryptophan
    plain_language
    One downstream metabolite activates an excitatory receptor.
    primary_references
    Quinolinate activation of N-methyl-D-aspartate ion channels in rat hippocampal neurons. · 1990 · https://pubmed.ncbi.nlm.nih.gov/1700844/ · DOI 10.1016/0304-3940(90)90098-t

    Tryptophan: transport, protein synthesis, neuroactive metabolites, NAD and microbial pathways (2026-09-19) · lines 274–280

    AI-assisted research curation; primary-abstract references and experimental limitations individually identified. Not publisher full text. · supports · Rat CA1 neuronal single-channel recording; 1.8 mM calcium. · source_derived_draft · unverified_draft

    ## tryptophan-quinolinate-nmda One downstream metabolite activates an excitatory receptor. Quinolinate at 75 micromolar opened NMDA channels in cultured rat hippocampal neurons in calcium-containing, magnesium-free recording solution. Model: Rat CA1 neuronal single-channel recording; 1.8 mM calcium. Limitations: Quinolinate is not tryptophan itself; bath concentration is not a dietary dose. Evidence access: Primary abstract Quinolinate activation of N-methyl-D-aspartate ion channels in rat hippocampal neurons. · 1990 · https://pubmed.ncbi.nlm.nih.gov/1700844/ · DOI 10.1016/0304-3940(90)90098-t
    Complete structured claim and evidence

  7. Theanine inhibited radioligand binding at NMDA glycine-site sites in rat cortical preparations.

    L-Theanine → Rat NMDA-type glutamate receptors, subunits unresolved source_derived_draftungraded
    Experimental context and source evidence
    evidence_span
    {"source_cache": "artifacts/theanine-research/12596867.abstract.txt", "locator": "Primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "eaa387f7967a1ff8e68eceb71fd3294881967066c5dc080fd27bacf8a01ce33d", "start_char": 0, "end_char": 643, "text_sha256": "eaa387f7967a1ff8e68eceb71fd3294881967066c5dc080fd27bacf8a01ce33d"}
    experimental_model
    Radioligand receptor-binding competition
    exposure
    Theanine competition with radiolabeled ligands
    limitations
    Binding displacement is not proof of functional agonism/antagonism at an oral human dose. Abstract wording for the 80-30000-fold IC50 comparison is ambiguous and is not used as a potency estimate.
    nutrient_topic
    L-Theanine research collection; topical membership is not evidence of a direct dietary effect. · L-Theanine
    organism
    Rat cortical preparations
    plain_language
    A binding assay identifies a possible receptor interaction while leaving functional and clinical effects unresolved.
    primary_references
    [theanine-p12596867] Inhibition by theanine of binding of [3H]AMPA, [3H]kainate, and [3H]MDL 105,519 to glutamate receptors. (2002). https://pubmed.ncbi.nlm.nih.gov/12596867/ DOI: 10.1271/bbb.66.2683
    tissue_or_cell_type
    AMPA, kainate and NMDA glycine-site binding

    L-Theanine: metabolism, neural signaling, nutrient connections and human outcomes (2026-09-17) · lines 315–326

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Radioligand receptor-binding competition · source_derived_draft · unverified_draft

    ### theanine-binding-nmda Theanine inhibited radioligand binding at NMDA glycine-site sites in rat cortical preparations. Condition category: normal nutrient_topic: L-Theanine research collection; topical membership is not evidence of a direct dietary effect. plain_language: A binding assay identifies a possible receptor interaction while leaving functional and clinical effects unresolved. organism: Rat cortical preparations tissue_or_cell_type: AMPA, kainate and NMDA glycine-site binding experimental_model: Radioligand receptor-binding competition limitations: Binding displacement is not proof of functional agonism/antagonism at an oral human dose. Abstract wording for the 80-30000-fold IC50 comparison is ambiguous and is not used as a potency estimate. exposure: Theanine competition with radiolabeled ligands evidence_span: {"source_cache": "artifacts/theanine-research/12596867.abstract.txt", "locator": "Primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "eaa387f7967a1ff8e68eceb71fd3294881967066c5dc080fd27bacf8a01ce33d", "start_char": 0, "end_char": 643, "text_sha256": "eaa387f7967a1ff8e68eceb71fd3294881967066c5dc080fd27bacf8a01ce33d"} [theanine-p12596867] Inhibition by theanine of binding of [3H]AMPA, [3H]kainate, and [3H]MDL 105,519 to glutamate receptors. (2002). https://pubmed.ncbi.nlm.nih.gov/12596867/ DOI: 10.1271/bbb.66.2683
    Complete structured claim and evidence

In the sources

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