Convergence in the olfactory system: quantitative aspects of odour sensitivity

Abstract

The olfactory organ offers a model of a neural system where a large number of receptor cells converge onto a small number of secondary neurones. A mathematical analysis of the effects of neural convergence in terms of response probability of secondary cells has been carried out. The parameters studied have been the ratio of neural convergence, the individual response probability of primary neurones, and the acceptor distribution over the receptor cells. The results indicate that a neural system with a high convergence ratio can detect stimuli at intensities below the one which is commonly used to demonstrate a conspicuous response in the primary neurones. An analysis of the response probabilities of secondary neurones in a system where the olfactory receptor cells have a multimodal sensitivity v. a unimodal one, shows that the response probabilities remain the same as long as the total number of "acceptors" is the same in the two modalities. © 1978.