Neurosteroids modulate epileptiform activity and associated high-frequency oscillations in the piriform cortex

Area of Science:

• Neuroscience
• Neuropharmacology
• Epileptology

Background:

• Allotetrahydrodeoxycorticosterone (THDOC) is a neurosteroid that enhances GABAA receptor signaling, increasing inhibitory currents in the brain.
• The piriform cortex is a highly excitable brain region involved in seizure generation and maintenance.
• High-frequency oscillations (HFOs) are associated with epileptiform activity and can serve as biomarkers for seizures.

Purpose of the Study:

• To investigate the role of THDOC in modulating interictal- and ictal-like activity in the rat piriform cortex.
• To examine the effect of THDOC on associated high-frequency oscillations (HFOs).
• To elucidate the mechanisms by which THDOC influences neuronal excitability and epileptiform synchronization.

Main Methods:

• In vitro electrophysiological recordings were performed in rat piriform cortex slices.
• Interictal and ictal-like activities and associated HFOs were analyzed.
• The effects of THDOC on synchronous field potentials were assessed.

Main Results:

• THDOC increased the duration of interictal discharges in the anterior piriform cortex.
• THDOC decreased the duration of ictal discharges in both anterior and posterior piriform cortices.
• THDOC reduced the occurrence of HFOs and prolonged GABAA receptor-mediated synchronous field potentials.

Conclusions:

• THDOC modulates epileptiform synchronization in the piriform cortex, likely by potentiating GABAA receptor signaling.
• Neurosteroids like THDOC play a significant role in regulating neuronal excitability and controlling seizure occurrence.
• These findings contribute to understanding the neurosteroid basis of seizure control.