Simulation of CA3 region of hippocampus by kinetic models

The global activities of the hippocampal CA3 field which are induced by stimuli coming from entorhinal cortex have been investigated through computional experiments. The simulations are based on a mathematical model formulated within the frame of a kinetic theory of neural systems. To obtain a description closer to the real biological system, the kinetic model has been supplemented with elements describing the dynamics of neurotransmitters in synaptic clefts. Because high frequency activities occur in the CA3 field, elements for the description of receptor saturation and vesicle depletion phenomena have also been taken into account. The computational experiments show that CA3 model reacts to simulated stimuli from entorhinal sources activating the pyramidal neurons. This activity self-organizes within some limited areas, and spreads to the whole CA3 as a patterned reverberation of short period which requires both excitatory and inhibitory neural populations. The reverberating activity is then stopped by massive inhibition produced by slow-inhibitory neural population. The relationships between the parameters linked to the synaptic dynamic and the elements characterizing these patterns have been investigated.