Objective: Genetic Absence Epilepsy Rats from Strasbourg (GAERS) show a resistance to secondary generalization of focal limbic seizures evoked by kindling. The substantia nigra pars reticulata (SNR) is involved in the propagation and modulation of seizures in kindling. We first examined the role of the SNRanterior and SNRposterior subregions in the resistance to the development of kindling in GAERS. Subsequently, to determine whether kindling resistance relates to differential sensitivity of γ-aminobutyric acid γ-aminobutyric acid (GABA)ergic or dopaminergic SNR neurons to kindling, we studied the effects of kindling-inducing stimulations on parvalbumin (PRV; GABAergic neuron marker) or tyrosine hydroxylase (TH; dopaminergic neuron marker) immunoreactivity (ir), respectively, in GAERS and in nonepileptic control (NEC) Wistar rats that lack kindling resistance.
Methods: Adult male GAERS were implanted with a stimulation electrode in the amygdala, and bilateral injection cannulas for lidocaine or saline injection (30 min before each kindling stimulation until the animals reached three stage 5 seizures or the 22 stimulations) into the SNRanterior or SNRposterior . In another experiment, PRV-ir in SNRanterior and SNRposterior and TH-ir in SNRposterior only were densitometrically compared in GAERS-SHAM, NEC-SHAM GAERS-STIM, and NEC-STIM animals (6 kindling stimulations).
Results: Bilateral SNRposterior infusions of lidocaine eliminated the kindling resistance and resulted in stage 5 generalized motor seizures in all kindled rats. Bilateral lidocaine infusions in the SNRanterior failed to alter the kindling resistance in GAERS. PRV-ir in the SNRposterior was unaltered in GAERS-STIM but increased in NEC-STIM group. Cellular TH-ir in the SNRposterior significantly increased by kindling stimulations in both NEC-STIM and GAERS-STIM groups.
Significance: The kindling resistance in GAERS is mediated by the SNRposterior in a lidocaine-sensitive manner. The insensitivity to kindling stimulation of PRV-ir in SNRposterior of GAERS but not NEC rats, implicate GABAergic SNRposterior neurons in kindling resistance. In contrast, the observed stimulation-specific increase in TH-ir in the SNRposterior is unrelated to kindling resistance.
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http://dx.doi.org/10.1111/epi.13204 | DOI Listing |
Neurosci Bull
January 2025
Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, College of Pharmaceutical Sciences, The Second Affiliated Hospital of Zhejiang Chinese Medical University (Xinhua Hospital), Zhejiang Chinese Medical University, Hangzhou, 310053, China.
Approximately 30%-40% of epilepsy patients do not respond well to adequate anti-seizure medications (ASMs), a condition known as pharmacoresistant epilepsy. The management of pharmacoresistant epilepsy remains an intractable issue in the clinic. Its early prediction is important for prevention and diagnosis.
View Article and Find Full Text PDFNaunyn Schmiedebergs Arch Pharmacol
December 2024
Department of Physiology, Medical School, University of Ondokuz Mayis, Samsun, 55139, Türkiye.
This study aimed to investigate the role of acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) inhibitor rivastigmine (RIVA) in the pentylenetetrazole (PTZ)- induced kindling model of epilepsy. The current study consists of three steps; 1) Saline or RIVA (0.5, 1, and 2 mg/kg) was administered intraperitoneally (i.
View Article and Find Full Text PDFAnn Neurol
February 2025
Department of Medicinal Chemistry, Faculty of Pharmacy, Jagiellonian University Medical College, Krakow, Poland.
Objective: Excitotoxicity is a common hallmark of epilepsy and other neurological diseases associated with elevated extracellular glutamate levels. Thus, here, we studied the protective effects of (R)-AS-1, a positive allosteric modulator (PAM) of glutamate uptake in epilepsy models.
Methods: (R)-AS-1 was evaluated in a range of acute and chronic seizure models, while its adverse effect profile was assessed in a panel of standard tests in rodents.
CNS Neurosci Ther
November 2024
Department of Pharmacology, Faculty of Pharmacy, Bahauddin Zakariya University, Multan, Pakistan.
Background: The microbiota-gut-brain axis (MGBA) is a central nexus that integrates higher cognitive and emotional centers of the central nervous system (CNS) within the intricate functioning of the intestine. Accumulating evidence suggests that dysbiosis in the taxonomic diversity of gut flora plays a salient role in the progression of epilepsy and comorbid secondary complications.
Methods: In the current study, we investigated the impact of long-term oral bacteriotherapy (probiotics; 10 mL/kg; 10 colony-forming unit/ml) as an adjunctive treatment intervention with brivaracetam (BRV; 10 mg/kg) over 21 days on pentylenetetrazole (PTZ) induced augmented epileptic response and associated electrographical and behavioral perturbations in mice.
Epilepsy Res
November 2024
Department of Pharmaceutical Sciences and Drug Research, Punjabi University, Patiala 147002, India. Electronic address:
Objective: To assess the potential of bypassing mitochondrial complex I with idebenone to overcome drug resistance in a Rotenone corneal kindling (RCK) mouse model of mitochondrial refractory epilepsy.
Material And Method: Resistance was developed by administering rotenone 2.5 mg/kg intraperitoneally once and corneal kindling twice daily.
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