Spatiotemporal Synchronization of Neuronal Activity in a Hippocampal CA3 Network Model Including the O-LM Cell

Abstract

Neurons often cause bursting discharges in synchrony in the hippocampal CA3 region, which has rich excitatory and inhibitory recurrent connections. It has been supposed that the recurrent inhibition is important to synchronize the neuronal activity. Many types of interneurons exist in the CA3 region. In particular, oriens- lacunosum moleculare (O-LM) cells have a distinctive feature; the cells are resonant and have a resonance frequency in the theta range. In this paper, we investigated how the O-LM cells effectively promoted synchronization of neuronal activity using a hippocampal CA3 network model. As a result, although synchronization of spike bursts of pyramidal cells was improved a little due to the resonant activity of the O-LM cell in comparison with the network with fast- spiking inhibitory neuron, the synchronization was still poor. However, when the basket cells inhibited the O-LM cell unilaterally, synchronization of spike bursts of pyramidal cells was improved dramatically.