ROLE OF THE NET ARCHITECTURE IN PIRIFORM CORTEX ACTIVITY - ANALYSIS BY A MATHEMATICAL-MODEL

We present a mathematical analysis of the piriform cortex activity in rats. Experimental data were obtained by means of optical recording of fluorescent signals driven by neuronal activity. From these data, we determined the numerical value of the relaxation time:for the pyramida l cell activity in layers II and III aad the time latency map for bulb activation. Our model for the piriform cortex is based on pairs of ex citatory and inhibitory neurons which correspond to pyramidal cells of layers II and III and to their inhibitory associated interneurons res pectively; pyramidal cells are also interconnected through short and l ong range association fiber systems. Under such conditions, the;model outputs resemble closely the experimental observations: (1) a double-b umped response to a strong and short stimulation; (2) oscillatory beha vior under weak sustained stimulation conditions; (3) propagation of t raveling activity waves; and (4) pacemaker activity when clusters of n eurons are preferentially coupled.