The activity in our model appears to be different from what has been reported in hippocampus or neocortex. We have cells with intrinsic oscillations and GABAergic modulation of this activity. The advantages of this in vitro model of the sharp wave include that it is generated in normal media, the onset and offset of the gamma oscillations are reproducible, intracellular recording techniques can be easily applied, and pharmacological techniques are also easy to apply. Another functional aspect of our work is the generation of seizure activity. Area CA3 of the hippocampus is one region that can initiate seizure activity.
Entorhinal cortex is another.
The capabilities of the other hippocampal and retrohippocampal regions are much more limited, but the inter-regional connectivity provides multiple access points for events generated in entorhinal cortex. We are investigating the mechanisms by which individual regions initiate seizure activity and the mechanisms by which such activity invades neighboring regions. A third functional aspect of our work is the interaction of cortical inputs in each region. This relates most directly to the circuitry underlying navigational behavior. We are studying the combined effects of inputs such as the examples given on identified cells throughout the retrohippocampal regions.