Threshold for epileptiform activity is elevated in prion knockout mice

Area of Science:

• Neuroscience
• Molecular Biology
• Genetics

Background:

• The function of prion protein (PrP) in the nervous system is not fully understood.
• Prion diseases involve PrP aggregation, potentially disrupting normal function.
• The link between PrP loss of function and neurodegeneration or clinical features like epilepsy in Creutzfeldt-Jakob disease (CJD) requires investigation.

Purpose of the Study:

• To investigate the role of PrP loss of function in altered seizure susceptibility.
• To determine if PrP deficiency contributes to epilepsy initiation, as observed in CJD patients.

Main Methods:

• Utilized acute epilepsy models in vitro using brain slices from PrP knockout (Prnp0/0) and control mice.
• Applied various convulsant treatments, including zero-magnesium, bicuculline, and pentylenetetrazol.
• Assessed the generation of spontaneous epileptiform activity in response to convulsants.

Main Results:

• Prnp0/0 mice exhibited a higher seizure threshold compared to control mice.
• Longer delays and/or higher convulsant concentrations were required to induce epileptiform activity in Prnp0/0 mice across all models.
• These findings indicate increased resistance to seizure initiation in the absence of PrP.

Conclusions:

• Loss of PrP function does not predispose to seizure initiation.
• The increased seizure threshold in Prnp0/0 mice suggests PrP's role may be protective against epilepsy.
• This challenges the hypothesis that PrP loss of function underlies epilepsy in CJD.