Researchers study the roundworm C. elegans to understand how its simple nervous system of 302 neurons controls behavior. This worm's neural connections are fully mapped, making it a great model for research.

MIT researchers are focusing on behaviors like feeding and navigation, hoping to learn about how neural circuits give rise to behavior in more complex animals.

They have discovered how changes in the worm's feeding behavior happen through neural mechanisms. They've also mapped how each neuron influences different behaviors, potentially shedding light on human brain activity. The worm uses neuromodulators, similar to those in humans, to control its actions, suggesting that these mechanisms might be universal across species.

The MIT researchers have unveiled how C. elegans manages stable behavioral states, like alternating between foraging and eating, influenced by environmental cues. A significant study detailed the worm's serotonin system, showing how this neurotransmitter affects behavior.

Possible generalization all the way up to mammals and humans

“Our studies of how the serotonin system works to control behavior have already revealed basic aspects of serotonin signaling that we think ought to generalize all the way up to mammals,” says research leader Steven Flavell in an MIT press release. “By studying the way that the brain implements these long-lasting states, we can tap into these basic features of neuronal function."

This work could have implications for understanding serotonin's role in human behavior.

The MIT researchers use special microscopes that can move along with the worms as they explore, allowing them to simultaneously track every behavior and measure the activity of every neuron in the brain. Using these data, they have created computational models that can accurately capture the relationship between brain activity and behavior.

Flavell adds that, with the resolution that you can get studying specific C. elegans neurons and the way that they implement behavior, "we can uncover fundamental features of the way that neurons act.”