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Updated: Aug 30, 2026
Preparation and Implantation of Electrodes for Electrically Kindling VGAT-Cre Mice to Generate a Model for Temporal Lobe Epilepsy
Published on: August 17, 2021
Increased persistent sodium currents in rat entorhinal cortex layer V neurons in a post-status epilepticus model of
Newton Agrawal1, Angel Alonso, David S Ragsdale
1Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, Quebec H3A 2B4, Canada.
Purpose:
Spontaneous seizures in rats emerge several weeks after induction of status epilepticus with pharmacologic treatment or electrical stimulation, providing an animal model for human temporal lobe epilepsy. In this study, we investigated whether status epilepticus caused changes in the function of voltage-gated sodium channels in entorhinal cortex layer V neurons, a cellular group important for the genesis of limbic seizures.
Methods:
We induced status epilepticus in rats, by using lithium-pilocarpine, and then 2-12 weeks later, used whole-cell voltage-clamp to examine voltage-activated sodium currents of acutely dissociated layer V neurons.
Results:
Transient sodium currents of entorhinal cortex layer V neurons isolated from 9- to 12-week post-status epilepticus rats were similar to currents in age-matched controls; however, low-threshold persistent sodium currents were significantly larger. This increase in persistent activity was not seen 2-3 weeks after pilocarpine treatment; thus it occurred after a delay comparable to the delay in the appearance of spontaneous seizures.
Conclusions:
Increased persistent currents are expected to accentuate neuronal excitability and thus may contribute to the genesis of spontaneous seizures after status epilepticus.
