A recent study in PLOS Biology explored how positive scent memories from early life form, survive, and change inside the brain. Through a human survey and a series of mouse experiments, the study traces these memories from their first roots in the olfactory bulb to the wider networks that carry their emotional meaning later in life.

— Read more in How the Scent of Childhood Takes Root in the Brain at Psychology Today.

Now, two teams of scientists have managed to map the nose of a mouse. Using advanced genetic sequencing and imaging techniques, the researchers found that each of the 1,100 different types of olfactory receptors in the mouse nose occupied a distinct and predictable position, consistent from mouse to mouse.

— Read more in Scientists Unveil ‘Long Lost’ Map for Smell at The New York Times.

They found that Negritos, the hunter-gatherer group, had unusually well-preserved olfactory receptor genes. [...]

The findings suggest there is a strong evolutionary pressure to maintain these genes among Negritos compared with other populations, likely because smell plays a crucial role in foraging and hunting.

In addition, Negritos were more likely to carry genes associated with detecting earthy, fruity, and herbal smells, scents common in rainforest environments and often associated with edible plants and ripe fruit.

— Read more in Human sense of smell evolved with diets and lifestyle, genetic study suggests at Phys.org.