Comprised of only around 100,000 neurons, the Drosophila fruit fly brain is capable of highly complex behaviors. Getty Images

This link is in the spirit of appreciating the value of the lowliest members of our day to day encounters with nature, and the role they play in helping scientists better understand phenomena important to humans. Thanks to Kevin Jiang and the Harvard Gazette:

Where we get our sense of direction

Experiments reveal how visual cues reorganize course-sensing neurons in fruit flies

If you’ve ever woken up in the middle of the night to go to the bathroom and stumbled around in the dark, banging into walls or dressers in a room you’ve walked through countless times, you’ve experienced the effects of inadequately calibrated neurons.

In many animals, humans included, an accurate sense of direction is generated with the help of brain cells known as head direction neurons, which do so by incorporating two main streams of information — visual landmarks and positional estimates based on self-movement.

Without the former, our ability to navigate even familiar locations degrades. But given a visual landmark — like the glow of an alarm clock or the shadow of a door — our internal map of the environment refreshes, and we can make our way with ease once again.

A similar process occurs in fruit flies, which use so-called compass neurons to keep track of the orientation of their heads and body. In a new study, published in Nature today, Harvard Medical School (HMS) neuroscientists have now decoded how visual cues can rapidly reorganize the activity of these compass neurons to maintain an accurate sense of direction.

By tracking individual neurons in fruit flies as they navigate a virtual reality environment, the researchers shed light on neural mechanisms that allow organisms to build a spatial map of their world, as well as processes involved in short-term memory.

“When we look at the pattern of connections between compass neurons and the visual system, we see that they are remodeled by visual experiences,” said senior study author Rachel Wilson, the Martin Family Professor of Basic Research in the Field of Neurobiology in the Blavatnik Institute at Harvard Medical School.

“These changes are happening over minutes and correspond with the timescale that we experience subjectively when we enter a new environment and explore it,” Wilson said. “To me, it’s remarkable that we can get insight into something as complicated as spatial navigation by studying a brain that’s smaller than a poppy seed.”

Read the whole article here.