Article ; Online: Extrasynaptic δGABAA receptors mediate resistance to migraine-like phenotype in rats.
The journal of headache and pain
2024 Volume 25, Issue 1, Page(s) 75
Abstract: Background: GABA, a key inhibitory neurotransmitter, has synaptic and extrasynaptic receptors on the postsynaptic neuron. Background GABA, which spills over from the synaptic cleft, acts on extrasynaptic delta subunit containing GABAA receptors. The ... ...
Abstract | Background: GABA, a key inhibitory neurotransmitter, has synaptic and extrasynaptic receptors on the postsynaptic neuron. Background GABA, which spills over from the synaptic cleft, acts on extrasynaptic delta subunit containing GABAA receptors. The role of extrasynaptic GABAergic input in migraine is unknown. We investigated the susceptibility to valid migraine-provoking substances with clinically relevant behavioral readouts in Genetic Absence Epilepsy of Rats Strasbourg (GAERS), in which the GABAergic tonus was altered. Subsequently, we screened relevant GABAergic mechanisms in Wistar rats by pharmacological means to identify the mechanisms. Methods: Wistar and GAERS rats were administered nitroglycerin (10 mg/kg) or levcromakalim (1 mg/kg). Mechanical allodynia and photophobia were assessed using von Frey monofilaments and a dark-light box. Effects of GAT-1 blocker tiagabine (5 mg/kg), GABAB receptor agonist baclofen (2 mg/kg), synaptic GABAA receptor agonist diazepam (1 mg/kg), extrasynaptic GABAA receptor agonists gaboxadol (4 mg/kg), and muscimol (0.75 mg/kg), T-type calcium channel blocker ethosuximide (100 mg/kg) or synaptic GABAA receptor antagonist flumazenil (15 mg/kg) on levcromakalim-induced migraine phenotype were screened. Results: Unlike Wistar rats, GAERS exhibited no reduction in mechanical pain thresholds or light aversion following nitroglycerin or levcromakalim injection. Ethosuximide did not reverse the resistant phenotype in GAERS, excluding the role of T-type calcium channel dysfunction in this phenomenon. Tiagabine prevented levcromakalim-induced mechanical allodynia in Wistar rats, suggesting a key role in enhanced GABA spillover. Baclofen did not alleviate mechanical allodynia. Diazepam failed to mitigate levcromakalim-induced migraine phenotype. Additionally, the resistant phenotype in GAERS was not affected by flumazenil. Extrasynaptic GABAA receptor agonists gaboxadol and muscimol inhibited periorbital allodynia in Wistar rats. Conclusion: Our study introduced a rat strain resistant to migraine-provoking agents and signified a critical involvement of extrasynaptic δGABAergic receptors. Extrasynaptic δ GABAA receptors, by mediating constant background inhibition on the excitability of neurons, stand as a novel drug target with a therapeutic potential in migraine. |
---|---|
MeSH term(s) | Animals ; Rats, Wistar ; Migraine Disorders/metabolism ; Migraine Disorders/drug therapy ; Migraine Disorders/physiopathology ; Rats ; Receptors, GABA-A/drug effects ; Receptors, GABA-A/metabolism ; Male ; Phenotype ; Disease Models, Animal ; Hyperalgesia/drug therapy ; Hyperalgesia/metabolism ; Epilepsy, Absence/drug therapy ; Epilepsy, Absence/physiopathology ; Nitroglycerin/pharmacology ; Nitroglycerin/toxicity ; Photophobia/etiology ; Photophobia/physiopathology |
Chemical Substances | Receptors, GABA-A ; Nitroglycerin (G59M7S0WS3) |
Language | English |
Publishing date | 2024-05-10 |
Publishing country | England |
Document type | Journal Article |
ZDB-ID | 2036768-5 |
ISSN | 1129-2377 ; 1129-2369 |
ISSN (online) | 1129-2377 |
ISSN | 1129-2369 |
DOI | 10.1186/s10194-024-01777-4 |
Database | MEDical Literature Analysis and Retrieval System OnLINE |
More links
Kategorien
In stock of ZB MED Cologne/Königswinter
Zs.A 5464: Show issues | Location: Je nach Verfügbarkeit (siehe Angabe bei Bestand) bis Jg. 1994: Bestellungen von Artikeln über das Online-Bestellformular Jg. 1995 - 2021: Lesesall (2.OG) ab Jg. 2022: Lesesaal (EG) |
Order via subito
This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.