MODELING INSECT OLFACTORY NEURON SIGNALING BY A NETWORK UTILIZING DISINHIBITION

A male moth locates a conspecific female by detecting her sexual-phero mone blend. This detection is carried out in the antennal lobe, the fi rst stage of olfactory information processing, where local inhibitory neurons and projection (relay) neurons interact, Antennal-lobe neurons exhibit low-frequency (< 10 Hz) background activity and bursting (> 1 00 Hz) activity in response to pheromone stimulation. We describe this behavior by a realistic biophysical neuron model, The bursting behavi or of the model is the result of both intrinsic cellular properties an d network interaction. A slowly activating and inactivating calcium ch annel provides a depolarizing current for bursting and disinhibition i s shown to be a feasible network mechanism for triggering this calcium channel. Small neural networks utilizing disinhibition are presented with local neurons intercalated between receptor and projection neuron s. The firing behaviors of projection neurons in response to stimulati on by the pheromone blend or its components are in accordance with exp erimental results, This network architecture offers an alternative vie w of olfactory processing from the classical architecture derived from vertebrate studies.