Abstract View CORTICAL IH PLAYS A ROLE IN THE GENERATION OF PAROXYSMAL ACTIVITIES
Slow neocortical paroxysmal activities are characterized by increased amplitude of depolarizing and hyperpolarizing envelopes in some neocortical neurons, compared to slow sleep oscillations (Steriade et al., 1998). Sudden depolarization leading to the next paroxysmal cycle starts when the majority of cortical neurons are hyperpolarized. At least two factors play a critical role in the generation of hyperpolarizing potentials. These are the Ca2+-dependent K+ current and the disfacilitation that result from the temporal absence of synaptic activities in the network. Here, in experiments and computational models we investigated the possible role of hyperpolarization-activated depolarizing current (Ih) of cortical neurons in the generation of paroxysmal onsets. In vivo intracellular recordings with Cs+ filled pipettes suggest that K+ currents are significantly implicated in the generation of hyperpolarizing potentials during seizures. Earlier data showed an