Neural mechanisms olfactory system

After considering the evolutionary origins of the olfactory system and some basic principles of olfaction, this brief review examines one of the most extensively studied examples of neural processing of semiochemical information the sex pheromone-specific olfactory subsystem in male moths. This male-specific subsystem can be viewed as representing an exaggeration of organizational principles and functional mechanisms that are characteristic of olfactory systems in general. 

Comparative and phylogenetic considerations such as those outlined in the preceding paragraphs readily lead to speculation that the olfactory systems of modern animals share common antecedents and therefore probably also share common principles of functional organization and information processing. We might ask, What attributes of chemical stimuli do olfactory systems analyze and encode How are those features mapped in "neural space" at various levels of the olfactory pathway How are cells of the pathway organized, and what mechanisms do they use, to accomplish this analysis of odors in the environment ... 

However, the solution of these fundamental problems will not bring a complete understanding of the olfactory code any more than the elucidation of retinal receptor transduction events has been able to clarify the neural mechanisms that underlie visual perception. The ORN is but the first element in a complex neural network. The operations of central olfactory networks are also poorly understood and the anatomical organization of the olfactory system appears in some respects to be fundamentally different from the familiar topographically organized circuits of the other major sensory systems. Thus, much remains to be discovered before we will approach the kind of understanding we currently have of visual, auditory and somatosensory neural network function. 

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