An electrical circuit model of chemoreceptor cells based on adaptation and disadaptation time constants: implications for temporal filtering

Chemoreceptor cells have temporally dynamic physiological properties that serve as filters for fluctuating odor patterns. A computational model, based on an electrical circuit, of a peripheral chemoreceptor cell was developed based on two time constants (τ1 and τ2) that model sensory adaptation and recovery from adaptation. With τ1 set to 0.1 s and τ2 to 3.8 s, our model receptor cell responded like real olfactory cells when presented with a series of odor pulse trains. As in real olfactory cells, changes in response magnitude and frequency filtering were observed with changes in stimulation frequency. When presented with chaotic stimulus patterns, model receptor cells responded with brief periods of current flow and adapted quickly. Decreases in the first time constant (τ1) decreased the response magnitude, while decreases in the second time constant (τ2) increased the response magnitude and pulse frequency resolution during chaotic odor stimulation. The two time constants are important for determining different filter properties of the chemoreceptor cells and define the temporal range of chemical fluctuations to which a single cell will respond.