Odor information processing and stress response

Animals, including humans, constantly monitor, recognize, and judge their surroundings and environment, and take appropriate and additional exploratory actions. As an initial step of these behavioral responses, multimodal sensory information is detected in the sensory organs, and then processed unimodally and/or crossmodally in parallel bottom-up and top-down pathways in the CNS. Compared to other sensory systems, elements of the olfactory system are highly diverse and complex due to the hundreds of receptors and three related odor sensor systems, leading to delayed research frontiers in the olfactory system. Since Buck and Axel first reported a wonderful repertoire of olfactory receptors 30 years ago, anatomical and physiological analysis of the olfactory system has rapidly advanced the understanding of complex structures such as combinatorial receptor codes for odors, odor maps in the olfactory bulb, TAARs for aversive odors, and impaired fear responses by genetic ablation of dorsal olfactory receptors.

The sense of smell acts as a very wide range of environmental sensors that inform us about our approach to odor sources such as delicious or rotten foods, predators or non-predators, healthy or sick persons, roses or other flowers, cedar or camphor trees. The various behaviors caused by odors, with or without stress and emotional responses, are basically associated with survival and reproduction in certain environmental conditions. This principle would lead to the general hypothesis that information processing in CNS for category-based behavior and stress / emotion is common to humans and animals such as laboratory mice. For example, the stress response to predator odors has been studied as a model for a variety of neuropsychiatric disorders, including PTSD. Our goal is to gain a better understanding of the research frontier of odor information processing and behavior, with and without stress and emotional responses, over the last 30 years and in the future. To that end, we collect a variety of the latest findings on odor-induced neural activity, behavior, stress, and emotions.

This Research Topic extends from odor coding in the olfactory epithelium and subsequent decoding of odors along the sensory pathway to odor-induced behaviors or stress responses or emotions. To this aim, the present Research Topic welcome the following topics (but is not limited to):

- Anatomy of the projections between the olfactory bulb and the primary or higher sensory areas
- Inhibitory systems in innate, selective or robust odor representations
- Inhibitory mechanisms for controlling behavior, stress responses or emotions.
- Excitatory and inhibitory networks
- Nerve cell types classification related to the formation of odor maps in the olfactory bulb and higher olfactory centers