A species dependent response to the pro-epileptic drug pentylentetrazole in birds

Epilepsy is common disorder that affects over 50 million people worldwide. Birds remain a promising yet largely under-explored model of epilepsy. This study reports the comparison of the response of two species of birds, Australian Parrots (APs) and Sparrows (SPs), to a pro-epileptic drug, Pentylenetetrazole (PTZ). PTZ injections caused myoclonic jerks (MCJs) and tonic clonic seizures (TCSs) in both species. The frequency of MCJs in APs was greater at the dose of 75 mg/kg compared to both 50 mg/kg and 25 mg/kg while it was not significantly different in SPs. The comparison of APs and SPs showed that the frequency of MCJs was greater in APs compared to SPs at 25 mg/kg and 75 mg/kg while its latency was reduced at 25 mg/kg and 50 mg/kg. Interestingly SPs had a reduced latency of TCSs compared to APs at 75 mg/kg. Glutamatergic and Gabaergic cell count was conducted to determine an association with the epileptic response to PTZ. The Glutamatergic cell counts for SPs was significantly greater than APs and conversely the Gabaergic cell counts in APs was higher compared to SPs. The reason for this difference in findings needs to be further investigated. This study shows that birds, and APs and SPs in particular, are a valid, interesting and under-explored model of epilepsy that should be further explored in order to understand the mysteries of epilepsy.