Target type: cellularcomponent
An axon part that is a gap in the myelin where voltage-gated sodium channels cluster and saltatory conduction is executed. [GOC:mh]
The node of Ranvier is a specialized structure in the myelinated axons of neurons, acting as a gap in the myelin sheath that surrounds the axon. It is characterized by a high concentration of voltage-gated sodium channels, which are crucial for the rapid propagation of action potentials along the axon.
The cellular components of the node of Ranvier include:
**1. Axon membrane:** This is the plasma membrane of the axon that forms the boundary of the node. It is enriched with voltage-gated sodium channels and potassium channels.
**2. Myelin sheath:** While the myelin sheath is absent at the node, it is present immediately adjacent to the node, forming the internodes. The myelin sheath is composed of Schwann cells (in the peripheral nervous system) or oligodendrocytes (in the central nervous system), which wrap around the axon multiple times, providing electrical insulation.
**3. Axon:** The axon itself is the long, slender projection of a neuron that transmits nerve impulses. Within the node, the axon lacks the myelin sheath, allowing for the concentration of ion channels.
**4. Basal lamina:** This thin, extracellular matrix layer surrounds the axon and the myelin sheath. It provides structural support and helps to regulate the environment around the node.
**5. Extracellular space:** The space between the axon membrane and the myelin sheath at the node is filled with extracellular fluid. This fluid contains ions and other molecules that are important for the function of the node.
**6. Perinodal astrocytes:** In the central nervous system, astrocytes are glial cells that extend processes to the node of Ranvier. These processes interact with the node and contribute to its function.
These cellular components work together to ensure the efficient propagation of action potentials along the axon. The concentration of sodium channels at the node allows for rapid depolarization, while the myelin sheath provides insulation that prevents current leakage. The presence of potassium channels ensures the repolarization of the axon, restoring the membrane potential for the next action potential.'
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| Protein | Definition | Taxonomy |
|---|---|---|
| Sodium channel protein type 8 subunit alpha | A sodium channel protein type 8 subunit alpha that is encoded in the genome of human. [PRO:WCB, UniProtKB:Q9UQD0] | Homo sapiens (human) |
| Myocilin | A myocilin that is encoded in the genome of human. [PRO:DNx, UniProtKB:Q99972] | Homo sapiens (human) |
| Sodium channel protein type 2 subunit alpha | A sodium channel protein type 2 subunit alpha that is encoded in the genome of human. [PRO:WCB, UniProtKB:Q99250] | Homo sapiens (human) |
| Sodium channel protein type 1 subunit alpha | A sodium channel protein type 1 subunit alpha that is encoded in the genome of human. [PRO:WCB, UniProtKB:P35498] | Homo sapiens (human) |
| Potassium voltage-gated channel subfamily KQT member 2 | A voltage-gated potassium channel subunit KCNQ2 that is encoded in the genome of human. [] | Homo sapiens (human) |
| Potassium voltage-gated channel subfamily KQT member 3 | A voltage-gated potassium channel subunit KCNQ3 that is encoded in the genome of human. [] | Homo sapiens (human) |
| Compound | Definition | Classes | Roles |
|---|---|---|---|
| phenytoin | imidazolidine-2,4-dione | anticonvulsant; drug allergen; sodium channel blocker; teratogenic agent | |
| N-(2-aminoethyl)-5-chloro-1-naphthalenesulfonamide | naphthalenes; sulfonic acid derivative | ||
| amiodarone | amiodarone : A member of the class of 1-benzofurans that is 1-benzofuran substituted by a butyl group at position 2 and a 4-[2-(diethylamino)ethoxy]-3,5-diiodobenzoyl group at position 3. It is a cardiovascular drug used for the treatment of cardiac dysrhythmias. Amiodarone: An antianginal and class III antiarrhythmic drug. It increases the duration of ventricular and atrial muscle action by inhibiting POTASSIUM CHANNELS and VOLTAGE-GATED SODIUM CHANNELS. There is a resulting decrease in heart rate and in vascular resistance. | 1-benzofurans; aromatic ketone; organoiodine compound; tertiary amino compound | cardiovascular drug |
| amitriptyline | amitriptyline : An organic tricyclic compound that is 10,11-dihydro-5H-dibenzo[a,d][7]annulene substituted by a 3-(dimethylamino)propylidene group at position 5. Amitriptyline: Tricyclic antidepressant with anticholinergic and sedative properties. It appears to prevent the re-uptake of norepinephrine and serotonin at nerve terminals, thus potentiating the action of these neurotransmitters. Amitriptyline also appears to antagonize cholinergic and alpha-1 adrenergic responses to bioactive amines. | carbotricyclic compound; tertiary amine | adrenergic uptake inhibitor; antidepressant; environmental contaminant; tropomyosin-related kinase B receptor agonist; xenobiotic |
| chlorpromazine | chlorpromazine : A substituted phenothiazine in which the ring nitrogen at position 10 is attached to C-3 of an N,N-dimethylpropanamine moiety. Chlorpromazine: The prototypical phenothiazine antipsychotic drug. Like the other drugs in this class chlorpromazine's antipsychotic actions are thought to be due to long-term adaptation by the brain to blocking DOPAMINE RECEPTORS. Chlorpromazine has several other actions and therapeutic uses, including as an antiemetic and in the treatment of intractable hiccup. | organochlorine compound; phenothiazines; tertiary amine | anticoronaviral agent; antiemetic; dopaminergic antagonist; EC 3.4.21.26 (prolyl oligopeptidase) inhibitor; phenothiazine antipsychotic drug |
| cifenline | diarylmethane | ||
| haloperidol | haloperidol : A compound composed of a central piperidine structure with hydroxy and p-chlorophenyl substituents at position 4 and an N-linked p-fluorobutyrophenone moiety. Haloperidol: A phenyl-piperidinyl-butyrophenone that is used primarily to treat SCHIZOPHRENIA and other PSYCHOSES. It is also used in schizoaffective disorder, DELUSIONAL DISORDERS, ballism, and TOURETTE SYNDROME (a drug of choice) and occasionally as adjunctive therapy in INTELLECTUAL DISABILITY and the chorea of HUNTINGTON DISEASE. It is a potent antiemetic and is used in the treatment of intractable HICCUPS. (From AMA Drug Evaluations Annual, 1994, p279) | aromatic ketone; hydroxypiperidine; monochlorobenzenes; organofluorine compound; tertiary alcohol | antidyskinesia agent; antiemetic; dopaminergic antagonist; first generation antipsychotic; serotonergic antagonist |
| imipramine | imipramine : A dibenzoazepine that is 5H-dibenzo[b,f]azepine substituted by a 3-(dimethylamino)propyl group at the nitrogen atom. Imipramine: The prototypical tricyclic antidepressant. It has been used in major depression, dysthymia, bipolar depression, attention-deficit disorders, agoraphobia, and panic disorders. It has less sedative effect than some other members of this therapeutic group. | dibenzoazepine | adrenergic uptake inhibitor; antidepressant; EC 3.4.21.26 (prolyl oligopeptidase) inhibitor |
| lamotrigine | 1,2,4-triazines; dichlorobenzene; primary arylamine | anticonvulsant; antidepressant; antimanic drug; calcium channel blocker; EC 3.4.21.26 (prolyl oligopeptidase) inhibitor; environmental contaminant; excitatory amino acid antagonist; geroprotector; non-narcotic analgesic; xenobiotic | |
| mexiletine | mexiletine : An aromatic ether which is 2,6-dimethylphenyl ether of 2-aminopropan-1-ol. Mexiletine: Antiarrhythmic agent pharmacologically similar to LIDOCAINE. It may have some anticonvulsant properties. | aromatic ether; primary amino compound | anti-arrhythmia drug |
| nifedipine | Nifedipine: A potent vasodilator agent with calcium antagonistic action. It is a useful anti-anginal agent that also lowers blood pressure. | C-nitro compound; dihydropyridine; methyl ester | calcium channel blocker; human metabolite; tocolytic agent; vasodilator agent |
| nitrendipine | nitrendipine : A dihydropyridine that is 1,4-dihydropyridine substituted by methyl groups at positions 2 and 6, a 3-nitrophenyl group at position 4, a ethoxycarbonyl group at position 3 and a methoxycarbonyl group at position 5. It is a calcium-channel blocker used in the treatment of hypertension. Nitrendipine: A calcium channel blocker with marked vasodilator action. It is an effective antihypertensive agent and differs from other calcium channel blockers in that it does not reduce glomerular filtration rate and is mildly natriuretic, rather than sodium retentive. | C-nitro compound; dicarboxylic acids and O-substituted derivatives; diester; dihydropyridine; ethyl ester; methyl ester | antihypertensive agent; calcium channel blocker; geroprotector; vasodilator agent |
| phenobarbital | phenobarbital : A member of the class of barbiturates, the structure of which is that of barbituric acid substituted at C-5 by ethyl and phenyl groups. Phenobarbital: A barbituric acid derivative that acts as a nonselective central nervous system depressant. It potentiates GAMMA-AMINOBUTYRIC ACID action on GABA-A RECEPTORS, and modulates chloride currents through receptor channels. It also inhibits glutamate induced depolarizations. | barbiturates | anticonvulsant; drug allergen; excitatory amino acid antagonist; sedative |
| tetracaine | tetracaine : A benzoate ester in which 4-N-butylbenzoic acid and 2-(dimethylamino)ethanol have combined to form the ester bond; a local ester anaesthetic (ester caine) used for surface and spinal anaesthesia. Tetracaine: A potent local anesthetic of the ester type used for surface and spinal anesthesia. | benzoate ester; tertiary amino compound | local anaesthetic |
| naphthazarin | naphthazarin : A naphthoquinone that is 1,4-naphthoquinone in which the hydrogens at positions 5 and 8 are replaced by hydroxy groups. naphthazarin: fish toxin; isolated for first time from the walnut onigurmi, Juglans mandshurica maxim var. Sieboldiana Makino; structure | hydroxy-1,4-naphthoquinone | acaricide; antibacterial agent; antineoplastic agent; apoptosis inducer; geroprotector; plant metabolite |
| pimozide | pimozide : A member of the class of benzimidazoles that is 1,3-dihydro-2H-benzimidazol-2-one in which one of the nitrogens is substituted by a piperidin-4-yl group, which in turn is substituted on the nitrogen by a 4,4-bis(p-fluorophenyl)butyl group. Pimozide: A diphenylbutylpiperidine that is effective as an antipsychotic agent and as an alternative to HALOPERIDOL for the suppression of vocal and motor tics in patients with Tourette syndrome. Although the precise mechanism of action is unknown, blockade of postsynaptic dopamine receptors has been postulated. (From AMA Drug Evaluations Annual, 1994, p403) | benzimidazoles; heteroarylpiperidine; organofluorine compound | antidyskinesia agent; dopaminergic antagonist; first generation antipsychotic; H1-receptor antagonist; serotonergic antagonist |
| 4-[(2,4,6-triamino-5-pyrimidinyl)azo]benzoic acid | benzoic acids | ||
| mexiletine hydrochloride | mexiletine hydrochloride : A hydrochloride composed of equimolar amounts of mexiletine and hydrogen chloride. | hydrochloride | anti-arrhythmia drug |
| diltiazem | diltiazem : A 5-[2-(dimethylamino)ethyl]-2-(4-methoxyphenyl)-4-oxo-2,3,4,5-tetrahydro-1,5-benzothiazepin-3-yl acetate in which both stereocentres have S configuration. A calcium-channel blocker and vasodilator, it is used as the hydrochloride in the management of angina pectoris and hypertension. Diltiazem: A benzothiazepine derivative with vasodilating action due to its antagonism of the actions of CALCIUM ion on membrane functions. | 5-[2-(dimethylamino)ethyl]-2-(4-methoxyphenyl)-4-oxo-2,3,4,5-tetrahydro-1,5-benzothiazepin-3-yl acetate | antihypertensive agent; calcium channel blocker; vasodilator agent |
| flupirtine | flupirtine: RN given refers to parent cpd without isomeric designation | aminopyridine | |
| sertindole | sertindole : A phenylindole that is 1H-indole which is substituted on the nitrogen by a p-chlorophenyl group, at position 5 by chlorine, and at position 3 by a piperidin-4-yl group, which is itself substituted on the nitrogen by a 2-(2-oxoimidazolidin-1-yl)ethyl group. | heteroarylpiperidine; imidazolidinone; organochlorine compound; organofluorine compound; phenylindole | alpha-adrenergic antagonist; H1-receptor antagonist; second generation antipsychotic; serotonergic antagonist |
| mibefradil | Mibefradil: A benzimidazoyl-substituted tetraline that selectively binds and inhibits CALCIUM CHANNELS, T-TYPE. | tetralins | T-type calcium channel blocker |
| tedisamil | tedisamil : A member of the class of diazabicyclononanes that is (1s,5s)-3,7-diazaspiro[bicyclo[3.3.1]nonane-9,1'-cyclopentane] in which the hydrogens at positions 3 and 7 are replaced by cyclopropylmethyl groups. It is a potassium channel blocker and an antiarrhythmic agent currently currently in development for the treatment of atrial fibrillation. | ||
| uk 68798 | aromatic ether; sulfonamide; tertiary amino compound | anti-arrhythmia drug; potassium channel blocker | |
| ezogabine | ezogabine : A substituted aniline that is benzene-1,2,4-triamine bearing ethoxycarbonyl and 4-fluorobenzyl substituents at positions N-1 and N-4 respectively. An anticonvulsant used to treat seizures associated with epilepsy in adults. ezogabine: structure in first source | carbamate ester; organofluorine compound; secondary amino compound; substituted aniline | anticonvulsant; potassium channel modulator |
| n-methylpiperidin-4-yl propionate | |||
| cns 5161 | CNS 5161: structure in first source | ||
| bms204352 | BMS204352: a calcium-sensitive opener of maxi-K potassium channels; structure in first source | ||
| senicapoc | senicapoc: a Gardos channel blocker; structure in first source | ||
| xe 991, anthracenone | 10,10-bis(4-pyridinylmethyl)-9(10H)-anthracenone: neurotransmitter release enhancer and potassium channel blocker; structure given in first source | anthracenes | |
| ica-121431 | ICA-121431: structure in first source | ||
| 1-(4-hydroxyphenyl)-3-(3-methoxyphenyl)thiourea | thioureas | ||
| N-(2,4,6-trimethylphenyl)-3-bicyclo[2.2.1]heptanecarboxamide | monoterpenoid | ||
| n-(6-chloropyridin-3-yl)-4-fluorobenzamide | N-(6-chloropyridin-3-yl)-4-fluorobenzamide: structure in first source | ||
| apigenin | Chamomile: Common name for several daisy-like plants (MATRICARIA; TRIPLEUROSPERMUM; ANTHEMIS; CHAMAEMELUM) native to Europe and Western Asia, now naturalized in the United States and Australia. | trihydroxyflavone | antineoplastic agent; metabolite |
| 2',3,4-trihydroxychalcone | 2',3,4-trihydroxychalcone: structure given in first source | catechols; chalcones | |
| gw-5074 | |||
| 2-ethyl-5-methoxy-n,n-dimethyltryptamine | 2-ethyl-5-methoxy-N,N-dimethyltryptamine: a 5-HT(6) receptor agonist; structure in first source | ||
| 10,10-bis((2-fluoro-4-pyridinyl)methyl)-9(10h)-anthracenone | DMP 543: neurotransmitter release enhancer; structure given in first source | anthracenes | |
| ica 27243 | N-(6-Chloropyridin-3-yl)-3,4-difluorobenzamide: a KCNQ2/3 channel activator; structure in first source | ||
| 5-chloro-2-methyl-3-(1,2,3,6-tetrahydro-4-pyridinyl)-1h-indole | 5-chloro-2-methyl-3-(1,2,3,6-tetrahydro-4-pyridinyl)-1H-indole: a 5-HT6 agonist; structure in first source | indoles | |
| tetrodotoxin | |||
| a 803467 | A 803467: an Nav1.8 sodium channel blocker; structure in first source | ||
| cnv1014802 | vixotrigine: a sodium channel blocker | ||
| zetekitoxin ab | zetekitoxin AB: a sodium channel blocker; isolated from the frog Atelopus zeteki; structure in first source | ||
| (r)-n-(4-(4-methoxyphenyl)thiazol-2-yl)-1-tosylpiperidine-2-carboxamide | (R)-N-(4-(4-methoxyphenyl)thiazol-2-yl)-1-tosylpiperidine-2-carboxamide: structure in first source | ||
| saxitoxin | saxitoxin : An alkaloid isolated from the marine dinoflagellates and cyanobacteria that causes paralytic shellfish poisoning. Saxitoxin: A compound that contains a reduced purine ring system but is not biosynthetically related to the purine alkaloids. It is a poison found in certain edible mollusks at certain times; elaborated by GONYAULAX and consumed by mollusks, fishes, etc. without ill effects. It is neurotoxic and causes RESPIRATORY PARALYSIS and other effects in MAMMALS, known as paralytic SHELLFISH poisoning. | alkaloid; carbamate ester; guanidines; ketone hydrate; paralytic shellfish toxin; pyrrolopurine | cyanotoxin; marine metabolite; neurotoxin; sodium channel blocker; toxin |
| gs-458967 | 6-(4-(trifluoromethoxy)phenyl)-3-(trifluoromethyl)(1,2,4)triazolo(4,3-a)pyridine: an anti-arrhythmia agent that inhibits late sodium current; structure in first source | ||
| ajmaline |