Seizure-like activity disrupts LTP in vitro.

Amnesia is one of the most common consequences of seizures. We modelled this phenomenon in the in vitro hippocampal slice preparation by examining effects of seizure-like activity on long-term potentiation (LTP). LTP is an expression of neuronal plasticity which has been correlated with learning. Electrographic seizures (EGSs) were induced in area CA1 by electrical stimulation of CA3. Trains of tetanic stimuli were then immediately delivered to the Schaffer collateral-CA1 pathway in order to induce LTP. The subsequent LTP in these test slices was significantly lower in magnitude compared to LTP in control slices (with no EGSs). LTP could be successfully induced in test slices 1 h after the EGS. EGSs alone produced no long-lasting effect on baseline responses. These results indicate that the hippocampal slice preparation may serve as a model system in which to study the mechanisms by which seizures can disrupt neuronal plasticity.