Sulfasalazine decreases mouse cortical hyperexcitability

Area of Science:

• Neuroscience
• Pharmacology
• Epilepsy Research

Background:

• Approximately 30% of epilepsy patients are unresponsive to current antiepileptic drugs (AEDs).
• Sulfasalazine (SAS), an FDA-approved drug, inhibits the cystine/glutamate antiporter system xc- (SXC) and has shown efficacy in reducing tumor-associated seizures.

Purpose of the Study:

• To evaluate the effect of SAS on pharmacologically induced network hyperexcitability.
• To determine if SAS can enhance seizure suppression when co-administered with existing AEDs.

Main Methods:

• In vitro whole-cell patch-clamp recordings from mouse cortical slices.
• Induction of epileptiform activity using bicuculline, 4-aminopyridine, and magnesium-free solutions.
• Voltage-sensitive dye (VSD) recordings to assess network activity spread.

Main Results:

• SAS reduced evoked excitatory postsynaptic currents and altered inhibitory postsynaptic currents.
• SAS decreased the duration of some epileptiform events and completely blocked 4-aminopyridine-induced events.
• Co-administration of SAS with topiramate (TPM) significantly reduced the spatiotemporal spread of hyperexcitable network activity.

Conclusions:

• Inhibition of SXC by SAS effectively decreases cortical network hyperexcitability.
• SAS demonstrates potential as an adjunctive therapy for epilepsy, particularly when combined with AEDs like TPM.
• Further research into SAS and other SXC inhibitors could lead to novel epilepsy treatments.