Camphor-Induced Seizures in Rats Increase the Potency of Gamma Oscillations During the Ictal Period, A Component that may Lead to Refractoriness in Seizure Control

Particularly in the evaluation of substances that can cause neuronal hyperexcitability, triggering refractoriness to antiepileptic drugs, this has always been of interest to science. This study investigated the neurobehavioral and electrocorticographic (ECoG) characteristics of seizures induced by camphorated oil in Wistar rats and compared them to those triggered by pentylenetetrazol (PTZ), a classical chemoconvulsant model. Male rats received intraperitoneal administration of camphor (470 mg/kg), and behavioral evolution was monitored to characterize seizure onset and progression. ECoG recordings from the motor cortex were acquired for 30 min to assess cortical oscillatory activity during ictal and interictal periods. Camphor administration elicited six distinct and rapidly evolving behavioral patterns culminating in generalized clonic seizures with loss of postural reflexes. ECoG analyses revealed cyclic high-power ictal discharges interspersed with low-power interictal activity, resembling PTZ-induced seizures but with lower potency. Evaluation of anticonvulsant efficacy demonstrated that camphor-induced seizures were refractory to phenobarbital and phenytoin, whereas diazepam and propofol significantly reduced β- and γ-band power and effectively controlled convulsive activity. These findings suggest that camphor produces a reproducible chemoconvulsant model characterized by prominent cortical excitability and partial pharmacoresistance, supporting its potential utility in neurotoxicological and neuropharmacological studies aimed at understanding seizure mechanisms and testing antiepileptic drug responsiveness.