Diminishing the number or activation of a certain type of potassium channel in the hippocampus ― an area important for memory ― of mice induces hyperexcitability in some brain regions similar to that seen in epilepsy. The study, published this week in Nature Neuroscience, could explain the basis of the hyperexcitability seen in some types of epilepsy.
Timothy Jegla and colleagues knocked out the gene for the potassium channel Kv12.2 in pyramidal neurons of the hippocampus. These mice displayed signs of random pyramidal neuron excitability and spontaneous seizures, similar to symptoms seen during some types of epilepsy. They also found similar results in wild-type mice when these potassium channels were blocked using pharmacological drugs. Though these results are only preliminary, they could be useful to understand the mechanisms that underlie some forms of epilepsy in humans.