A brief survey is presented of current knowledge on olfaction in rodents and the various roles that odors may play in modifying rodent behavior. Some species at least uti lize olfactory cues: to locate food items; to recognize their mother and mates; to mark territory; as an involuntary population density regulator; possibly to recognize predators; as a warning cue against a repellent or toxic ...

Odors are powerful stimuli that can focus the attention, elicit behaviors (or misbehaviors) and even resurrect forgotten memories. These actions are directed by the central nervous system, but they depend upon the initial transduction of chemical signals by olfactory receptor neurons. Electrophysiological recordings suggest that the responses of olfactory receptor neurons to odors are more dive...

Disorders of the senses of taste and smell are not uncommon, occurring in over three million adults in the United States alone. Olfactory dysfunction occurs in about half of the population between the ages of 65 and 80 years and in about three-quarters of those 80 years of age and older (Figure 1). Although rarely appreciated, taste and smell disorders have significant consequences for the pati...

Cyclic nucleotide-gated ion channels in olfactory sensory neurons (OSNs) are hypothesized to play a critical role in olfaction. However, it has not been demonstrated that the cAMP signaling is required for olfactory-based behavioral responses, and the contributions of specific adenylyl cyclases to olfaction have not been defined. Here, we report the presence of adenylyl cyclases 2, 3, and 4 in ...

BACKGROUND For olfaction, several studies have reported near-infrared spectroscopy (NIRS) signal changes in the orbitofrontal cortex (OFC) during odor stimulation. However, the roles of human OFC in olfactory cognition are less well understood. This study was designed to better understand the roles of OFC for olfaction. METHODS Hemodynamic responses for phenyl ethyl alcohol or citral in the O...

The olfactory system provides numerous functions to humans, influencing ingestive behavior, awareness of environmental hazards and social communication. Approximately 1/5 of the general population exhibit an impaired sense of smell. However, in contrast to the many affected, only few patients complain of their impairment. So how important is it for humans to have an intact sense of smell? Or is...

In the philosophy of perception, olfaction is the perennial problem child, presenting a range of difficulties to those seeking to define its proper referents, and its phenomenological content. Here, we argue that many of these difficulties can be resolved by recognizing the object-like representation of odors in the brain, and by postulating that the basic objects of olfaction are best defined ...

The routine test of olfaction need not lead to an ambiguous outcome, a rather widely held notion. A multiple-choice test of odor identification that avoided the difficulty of retrieving odor names yielded excellent resolution among the categories normosmic, hyposmic, and anosmic. The outcome agreed almost perfectly with a more complicated test of threshold and offered much encouragement for the...