HUMAN OLFACTORY NEURONS RESPOND TO ODOR STIMULI WITH AN INCREASE IN CYTOPLASMIC CA2+

The sense of smell allows terrestrial animals to collect information a bout the chemical nature of their environment through the detection of airborne molecules (7). In humans smell is believed to play an import ant role in protecting the organism from environmental hazards such as fire, gas leaks and spoiled food, in determining the flavor of foods, and perhaps in infant-parent bonding (8). In addition, the study of h uman olfaction is relevant to a number of medical problems that result in olfactory dysfunction, which can affect nutritional state, and to the study of the etiology of neurodegenerative diseases which manifest themselves in the olfactory epithelium (8, 26). Although much is know n about behavioral aspects of human olfaction (8), little is understoo d about the underlying cellular mechanisms in humans. Here we report t hat viable human olfactory neurons (HON) can be isolated from olfactor y tissue biopsies, and we find that HON respond to odorants with an in crease in intracellular calcium concentration ([Ca(i)]).