Relation of chemical structure to specificity of response in olfactory glomeruli.

Recent work on the mammalian olfactory system shows that sensory neurons expressing the same type of odor receptor converge their axons onto one or a few glomeruli. This nearly one-to-one correspondence between an odor receptor type and an olfactory glomerulus gives rise to the tuning specificity of bulbar mitral and tufted cells, such that individual cells are only activated by a range of odor molecules having a similar chemical structure. These findings now make it possible to analyze the molecular mechanisms involved in the functional differentiation of sensory neurons, as well as those involved in their specific connections with bulbar neurons.