Implications of relaxation dynamics in the synaptic control of olfactory cortex activity

In a previous work (Ballain et al., 1998. Biol. Cyber. 79, 323-336) we reported the analysis of a model for the piriform cortex activity in rats based on experimental data. In this paper, we study an extension of this model by supplementing it with equations for the post-synaptic conductance and/or the pre-synaptic activation threshold. We use the present modelʹs outputs to account for experimental data based on paired stimulation in the opossum or the rat, obtained either through electrical recording or optical mapping of the cortex activity. The model exhibits great robustness when it comes to large variation in synaptic characteristics. Model outputs mimic satisfactorily the three kind of responses to paired stimuli (Litaudon and Cattarelli, 1996. Eur. J. Neurosci. 8, 21-29) and the recovery of the excitable capacities as demonstrated by Haberly (1973. J. Neurophysiol. 36 (4), 789-802) and Ferreyra-Moyano et al. (1985. Brain Res. Bull. 15, 237-248).