The relationship between physicochemical properties of odor molecules and perceived odor quality is arguably one of the most important issues in olfaction and the rules governing this relationship remain unknown. Any given odor molecule will stimulate more than one type of receptor in the nose, perhaps hundreds, and this stimulation reflects itself in the neural code of the olfactory nervous sy...

Recent experiments in Drosophila demonstrate striking stereotypy in the neural architecture of the olfactory system. Functional imaging experiments in mammals and honeybees suggest a mechanism of odor coding that translates discrete patterns of activity in olfactory glomeruli into an odor image. Future experiments in Drosophila may permit a direct test of this odor-coding hypothesis.

Sensory processing circuits in the visual and olfactory systems receive input from complex, rapidly changing environments. Although patterns of light and plumes of odor create different distributions of activity in the retina and olfactory bulb, both structures use what appears on the surface similar temporal coding strategies to convey information to higher areas in the brain. We compare tempo...

Topographic projections are important for coding sensory information in the visual, auditory, and somatosensory systems but are of uncertain importance in the coding of olfactory information. We searched for topographic projections between olfactory receptor cells and the olfactory bulb of the rainbow trout Oncorhynchus mykiss. Anterograde axonal tracing with HRP revealed that the olfactory axo...

The mammalian nose employs several olfactory subsystems to recognize and transduce diverse chemosensory stimuli. These subsystems differ in their anatomical position within the nasal cavity, their targets in the olfactory forebrain, and the transduction mechanisms they employ. Here we report that they can also differ in the strategies they use for stimulus coding. Necklace glomeruli are the sol...