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The olfactory system is the sensory system that is responsible for the sense of smell (olfaction). It receives, processes and interprets odour information.
Brain evolution at the cellular level is understudied. Here, the authors compare olfactory circuits from three Drosophila species, finding species-specific connectivity patterns associated with food odours and suggesting that more connectivity may be related to learning performance.
The role of olfactory pathways in the development of neurodegeneration in Alzheimer’s disease is not well understood. Here, the authors show odor identification deficits are predictive of tau accumulation and progression in olfactory pathways, and that tau spreads from medial temporal lobe structures towards the olfactory system.
The detection, discrimination and categorization of odours are essential for survival across the animal kingdom. In this Review, Datta and co-workers describe and compare the neural circuits that mediate the processing of olfactory information and the key principles of olfactory coding in insects and mammals.
Innate fear-like responses are thought to involve the amygdala, but here a tetra-synaptic pathway is identified that mediates odour-evoked innate fear in mice.
Infant attachment to the mother in rodents and monkeys is shown to rely on regulation of hypothalamic oxytocin release by a serotonergic projection from the raphe nucleus.