Neuroanatomical Substrates of Olfaction

In mammals, the olfactory system is important for reproduction, emotional responses, neuroendocrine regulation, and the recognition of conspecifics, predators, and prey. The linkages between olfaction and other neural functions present interesting questions. For example, the perception of flavor is a combination of olfactory and gustatory signals. What is the circuitry that integrates olfaction and taste to produce the integral conscious awareness of flavor? Odors are known to evoke strong memories; what are the neural substrates of this phenomenon? In some species, the odor of an estrous female is absolutely necessary to trigger sexual behavior in males. In other species, odors are important but not essential. What are the substrates linking olfactory stimuli to behavioral and neuroendocrine control circuits, and what differences in neural circuitry underlie differential dependence on odors for sexual behavior? An essential framework for understanding these issues is the neuroanatomy and neurochemical organization of the olfactory system and its linkages to other parts of the brain.