Receptors, circuits, and behaviors: new directions in chemical senses.

The chemical senses, smell and taste, are the most poorly understood sensory modalities. In recent years, however, the field of chemosensation has benefited from new methods and technical innovations that have accelerated the rate of scientific progress. For example, enormous advances have been made in identifying olfactory and gustatory receptor genes and mapping their expression patterns. Genetic tools now permit us to monitor and control neural activity in vivo with unprecedented precision. New imaging techniques allow us to watch neural activity patterns unfold in real time. Finally, improved hardware and software enable multineuron electrophysiological recordings on an expanded scale. These innovations have enabled some fresh approaches to classic problems in chemosensation.