Olfactory system and energy metabolism: a two-way street

Olfactory perception guides daily decisions regarding food consumption, social interactions, and predator avoidance in all mammalian species. Volatile inputs, comprising odorants and pheromones, are relayed to the olfactory bulb (OB) from nasal sensory neurons cells and transferred to secondary processing regions within the brain. Olfaction has recently been shown to shape homeostatic and maladaptive processes of energy intake and expenditure through neuronal circuits involving the medial basal hypothalamus. Reciprocally, gastrointestinal hormones, such as ghrelin and leptin, the secretion of which depends on satiety and adiposity levels, might also influence olfactory sensitivity to alter food seeking behaviors. Here, in addition to reviewing recent updates on identifying these neuronal networks, we also discuss how bidirectional neurocircuits existing between olfactory and energy processing centers can become dysregulated during obesity.

Automated summary

Olfactory perception plays a crucial role in daily decision making in mammals, guiding food consumption, social interactions, and predator avoidance. Recent studies have shown that olfaction is involved in regulating energy intake and expenditure through neuronal circuits, and gastrointestinal hormones may also influence olfactory sensitivity and food seeking behaviors. This article reviews the identification of these neuronal networks and discusses how dysregulation of bidirectional neurocircuits between olfactory and energy processing centers may occur during obesity.