Influence of the olfactory organ on brain development

Abstract

The olfactory epithelium is a unique sensory structure that has the intrinsic ability to renew its receptor neurons naturally throughout the vertebrate lifetime. The olfactory epithelium is also a neurogenetic matrix that generates various cell populations during embryonic development and adulthood. Some of these cell types migrate to the forebrain and therefore contribute to brain formation. The molecules involved in cell migration and continuous reconnection of olfactory receptor neurons to the bulb are discussed. Experiments involving removal or transplants of the olfactory placode in amphibians suggest that the olfactory organ influences the development of the telencephalon. We believe that the olfactory organ has a morphogenetic influence and even possibly an inducing effect on the forebrain. This effect could be mediated by a number of organizing factors that we discuss. The profound influence of the olfactory organ on brain development underlines the importance of the olfactory organ for survival.