Researchers create a reference atlas for neural circuits in fruit fly larvae

March 28, 2014 by Bob Yirka report
The Multi-Worm Tracker software tracked time-varying contours of larvae. The time-varying contours carry information about how larvae behaved when specific neurons were activated by optogenetics. Credit: Vogelstein, Park, Ohyama et al.

(Medical Xpress)—A team of researchers from Johns Hopkins University and Janelia Farm Research Campus has developed a new technique for studying neural circuits that helps tie circuit activity to organism behavior. In their paper published in the journal Science, the team describes how they used light activated proteins in neurons in conjunction with statistical analysis to create a reference atlas that describes 29 individual fruit fly larvae phenotypes.

Figuring out what the brain is doing when an organism is performing tasks has proved to be very difficult. To help the process along, researchers study relatively simple organisms with far fewer neurons than higher level animals—they also tend to have relatively simple neural circuitry. Still, progress has been slow, to say the least. In this new effort, the researchers report that they have, for the first time, been able to create a table, or reference atlas, for the fruit fly larvae that links certain neural circuit activities with certain behaviors, such as backing up.

To figure out what the brain is doing when an organism is doing something, researchers have studied the brains of individual specimens (using fMRI, for example) as they go about their business. This approach has so far proven to be not only tedious, but results in data that applies to just a single organism. In this new effort, the researchers took a much different approach—they manipulated neurons to respond to light (using optogenetics) in the brains of 37,780 individual larva then trained cameras on them as they went about their business to record their movements. The recordings produced massive amounts of data that could only be crunched by a computer, which is why the team used to coax out patterns of behavior that could be linked to certain activities. In so doing, they wound up creating behavioral trees to describe the subtle differences between different movements. This allowed them to create an atlas that described 29 distinguishable activities that could be tied to certain neural circuitry activations.

The video will load shortly.
Behaviotype 1: Larva makes one small left head turn (appears right in this video) followed by a large right head turn (appears left in this video) and then initiates crawling, interrupted once more by a couple of short head turns; crawling gets faster and faster. For more information, see Video S1 in the Supplementary Video Captions section of the Supporting Online Material. Credit: Vogelstein et al., Science/AAAS

The video will load shortly.
Behaviotype 6: Larva makes one small right head turn (appears left in this video) followed by a large left head turn (appears right in this video) and then initiates crawling. Crawling is interrupted by few short head turns. For more information, see Video S12 in the Supplementary Video Captions section of the Supporting Online Material. Credit: Vogelstein et al., Science/AAAS
The creation of the atlas represents a significant step forward in mapping in an organism and paves the way for similar work on with more sophisticated neural networks. The researchers plan to next extend their research to adult fruit flies, and eventually, to mice.

Explore further: Study describes first maps of neural activity in behaving zebrafish

More information: Discovery of Brainwide Neural-Behavioral Maps via Multiscale Unsupervised Structure Learning, Science DOI: 10.1126/science.1250298

ABSTRACT
A single nervous system can generate many distinct motor patterns. Identifying which neurons and circuits control which behaviors has been a laborious piecemeal process, usually for one observer-defined behavior at a time. We present a fundamentally different approach to neuron-behavior mapping. We optogenetically activated 1,054 identified neuron lines in Drosophila larva and tracked the behavioral responses from 37,780 animals. Applying multiscale unsupervised structure learning methods to the behavioral data identified 29 discrete statistically distinguishable and observer-unbiased behavioral phenotypes. Mapping the neural lines to the behavior(s) they evoke provides a behavioral reference atlas for neuron subsets covering a large fraction of larval neurons. This atlas is a starting point for connectivity- and activity-mapping studies to further investigate the mechanisms by which neurons mediate diverse behaviors.

Related Stories

Study describes first maps of neural activity in behaving zebrafish

March 19, 2014
In a study published today in the scientific journal Neuron, neuroscientists at the Champalimaud Foundation, in collaboration with neuroscientists from Harvard University, describe the first activity maps at the resolution ...

Scientists identify neurons that control feeding behavior in Drosophila

June 14, 2013
Scientists at the University of Massachusetts Medical School have developed a novel transgenic system which allows them to remotely activate individual brain cells in the model organism Drosophila using ambient temperature. ...

Our brain has switch board to guide behavior in response to external stimuli

February 14, 2014
How do our brains combine information from the external world (sensory stimulation) with information on our internal state such as hunger, fear or stress? NERF scientists demonstrate that the habenula, a specific part in ...

New clues to memory formation may help better treat dementia

November 27, 2013
Do fruit flies hold the key to treating dementia? Researchers at the University of Houston (UH) have taken a significant step forward in unraveling the mechanisms of Pavlovian conditioning. Their work will help them understand ...

Researchers devise a method for reprogramming cells in urine into neural progenitor cells

December 10, 2012
(Medical Xpress)—Researchers in China have developed a technique for reprogramming cells found in urine into neural progenitor cells that are capable of growing into neurons. In their paper published in Nature Methods, ...

Recommended for you

Research reveals 'exquisite selectivity' of neuronal wiring in the cerebral cortex

August 21, 2017
The brain's astonishing anatomical complexity has been appreciated for over 100 years, when pioneers first trained microscopes on the profusion of branching structures that connect individual neurons. Even in the tiniest ...

Afternoon slump in reward response

August 21, 2017
Activation of a reward-processing brain region peaks in the morning and evening and dips at 2 p.m., finds a study of healthy young men published in The Journal of Neuroscience. This finding may parallel the drop in alertness ...

Researchers find monkey brain structure that decides if viewed objects are new or unidentified

August 18, 2017
A team of researchers working at the University of Tokyo School of Medicine has found what they believe is the part of the monkey brain that decides if something that is being viewed is recognizable. In their paper published ...

Artificial neural networks decode brain activity during performed and imagined movements

August 18, 2017
Artificial intelligence has far outpaced human intelligence in certain tasks. Several groups from the Freiburg excellence cluster BrainLinks-BrainTools led by neuroscientist private lecturer Dr. Tonio Ball are showing how ...

Study of nervous system cells can help to understand degenerative diseases

August 18, 2017
The results of a new study show that many of the genes expressed by microglia differ between humans and mice, which are frequently used as animal models in research on Alzheimer's disease and other neurodegenerative disorders.

How whip-like cell appendages promote bodily fluid flow

August 18, 2017
Researchers at Nagoya University have identified a molecule that enables cell appendages called cilia to beat in a coordinated way to drive the flow of fluid around the brain; this prevents the accumulation of this fluid, ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.