Beyond breathing: multimodal pathways connecting olfaction to autonomic nervous system modulation.

The interaction between olfaction and respiration has recently emerged as a central aspect of brain-body interactions. To date, most studies in this context, both in rodents and humans, have focused on how respiratory airflow rhythmically drives brain activity. In this review, we shift the focus to the modulatory effects of odorant molecules, which engage chemical, affective, and trigeminal pathways to elicit integrated sensory experiences and robust autonomic responses. We synthesize recent findings showing that the olfactory system, through its unique connectivity with limbic and autonomic networks, operates at the interface between exteroception and interoception. By modulating respiratory dynamics, and more generally autonomic nervous system activity, odors emerge as a multimodal signal capable of influencing brain-body interactions and supporting well-being.