Adenosine A1 Receptors Participate in Excitability Changes after Cortical Epileptic Afterdischarges in Immature Rats

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00023752%3A_____%2F23%3A43921210" target="_blank" >RIV/00023752:_____/23:43921210 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/67985823:_____/23:00579656 RIV/00216208:11130/23:10473010 RIV/00064203:_____/23:10473010

Výsledek na webu

<a href="https://www.mdpi.com/1424-8247/16/12/1733" target="_blank" >https://www.mdpi.com/1424-8247/16/12/1733</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.3390/ph16121733" target="_blank" >10.3390/ph16121733</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Adenosine A1 Receptors Participate in Excitability Changes after Cortical Epileptic Afterdischarges in Immature Rats

Popis výsledku v původním jazyce

Background: Postictal refractoriness, i.e., the inability to elicit a new epileptic seizure immediately after the first one, is present in mature animals. Immature rats did not exhibit this refractoriness, and it is replaced by postictal potentiation. In addition to the immediate postictal potentiation, there is a delayed potentiation present at both ages. These phenomena were studied using cortical epileptic afterdischarges as a model. Objective: We aimed to analyze participation of adenosine A1 receptors in postictal potentiation and depression. Methods: Adenosine A1 receptors were studied by means of Western blotting in the cerebral cortex with a focus on the age groups studied electrophysiologically. Stimulation and recording electrodes were implanted epidurally in 12- and 25-day-old rats. The first stimulation always induced conditioning epileptic afterdischarge (AD), and 1 min after its end, the stimulation was repeated to elicit the second, testing AD. Then, the drugs were administered and paired stimulations were repeated 10 min later. A selective agonist CCPA (0.5 and 1 mg/kg i.p.) and a selective antagonist DPCPX (0.1, 0.5 and 1 mg/kg i.p.) were used to examine the possible participation of adenosine A1 receptors. Results: Control younger animals exhibited potentiation of the testing AD and a moderate increase in both conditioning and testing ADs after an injection of saline. The A1 receptor agonist CCPA shortened both post-drug ADs, and neither potentiation was present. The administration of an antagonist DPCPX resulted in marked prolongation of the conditioning AD (delayed potentiation), and the second testing AD was shorter than the post-drug conditioning AD, i.e., there was no longer immediate potentiation of ADs. To eliminate effects of the solvent dimethylsulfoxide, we added experiments with DPCPX suspended with the help of Tween 80. The results were similar, only the prolongation of ADs was not as large, and the testing ADs were significantly depressed. The older control group exhibited a nearly complete suppression of the first testing AD. There was no significant change in the conditioning and testing ADs after CCPA (delayed potentiation was blocked). Both groups of DPCPX-treated rats (with DMSO or Tween) exhibited significant augmentation of delayed potentiation but no significant difference in the immediate depression. Adenosine A1 receptors were present in the cerebral cortex of both age groups, and their quantity was higher in 12- than in 25-day-old animals. Conclusions: An agonist of the A1 receptor CCPA suppressed both types of postictal potentiation in 12-day-old rats, whereas the A1 antagonist DPCPX suppressed immediate potentiation but markedly augmented the delayed one. Immediate postictal refractoriness in 25-day-old rats was only moderately (non-significantly) affected; meanwhile, the delayed potentiation was strongly augmented.

Název v anglickém jazyce

Adenosine A1 Receptors Participate in Excitability Changes after Cortical Epileptic Afterdischarges in Immature Rats

Popis výsledku anglicky

Background: Postictal refractoriness, i.e., the inability to elicit a new epileptic seizure immediately after the first one, is present in mature animals. Immature rats did not exhibit this refractoriness, and it is replaced by postictal potentiation. In addition to the immediate postictal potentiation, there is a delayed potentiation present at both ages. These phenomena were studied using cortical epileptic afterdischarges as a model. Objective: We aimed to analyze participation of adenosine A1 receptors in postictal potentiation and depression. Methods: Adenosine A1 receptors were studied by means of Western blotting in the cerebral cortex with a focus on the age groups studied electrophysiologically. Stimulation and recording electrodes were implanted epidurally in 12- and 25-day-old rats. The first stimulation always induced conditioning epileptic afterdischarge (AD), and 1 min after its end, the stimulation was repeated to elicit the second, testing AD. Then, the drugs were administered and paired stimulations were repeated 10 min later. A selective agonist CCPA (0.5 and 1 mg/kg i.p.) and a selective antagonist DPCPX (0.1, 0.5 and 1 mg/kg i.p.) were used to examine the possible participation of adenosine A1 receptors. Results: Control younger animals exhibited potentiation of the testing AD and a moderate increase in both conditioning and testing ADs after an injection of saline. The A1 receptor agonist CCPA shortened both post-drug ADs, and neither potentiation was present. The administration of an antagonist DPCPX resulted in marked prolongation of the conditioning AD (delayed potentiation), and the second testing AD was shorter than the post-drug conditioning AD, i.e., there was no longer immediate potentiation of ADs. To eliminate effects of the solvent dimethylsulfoxide, we added experiments with DPCPX suspended with the help of Tween 80. The results were similar, only the prolongation of ADs was not as large, and the testing ADs were significantly depressed. The older control group exhibited a nearly complete suppression of the first testing AD. There was no significant change in the conditioning and testing ADs after CCPA (delayed potentiation was blocked). Both groups of DPCPX-treated rats (with DMSO or Tween) exhibited significant augmentation of delayed potentiation but no significant difference in the immediate depression. Adenosine A1 receptors were present in the cerebral cortex of both age groups, and their quantity was higher in 12- than in 25-day-old animals. Conclusions: An agonist of the A1 receptor CCPA suppressed both types of postictal potentiation in 12-day-old rats, whereas the A1 antagonist DPCPX suppressed immediate potentiation but markedly augmented the delayed one. Immediate postictal refractoriness in 25-day-old rats was only moderately (non-significantly) affected; meanwhile, the delayed potentiation was strongly augmented.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

30104 - Pharmacology and pharmacy

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

V - Vyzkumna aktivita podporovana z jinych verejnych zdroju

Rok uplatnění

2023

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Pharmaceuticals

ISSN

1424-8247

e-ISSN

1424-8247

Svazek periodika

16

Číslo periodika v rámci svazku

12

Stát vydavatele periodika

CH - Švýcarská konfederace

Počet stran výsledku

18

Strana od-do

1733

Kód UT WoS článku

001131479900001

EID výsledku v databázi Scopus

2-s2.0-85180660550