Summary: Scientists have identified two neural mechanisms,” Walk-OFF” and” Brake”, that control stopping behavior in fruit flies. Using epigenetics, they activated certain neurons to halt travel movements under red light.
These mechanisms are context-dependent, with” Walk-OFF” controlling stopping during feeding and” Brake” during grooming. This finding makes it easier to understand how the brain regulates movements, which may help with future research into how other animals ‘ neural pathways are handled.
Important Facts:
- Two neural mechanisms,” Walk-OFF” and” Brake”, control stopping in flies.
- Red light-activated neurons temporarily halt travel movements.
- The systems are context-specific, depending on activities like feeding or grooming.
Origin: Max Planck Institute
Ever wish you could prevent the fruit fly from fluttering in its tracks on your home shop?
Researchers at the Max Planck Florida Institute for Neuroscience have developed fly that stop under red lights. They did so by discovering the exact neurological systems that govern stopping.
Their results, published this month in , Nature, have repercussions much beyond controlling fly behavior. They show how the mind engages various neural pathways in response to economic circumstances.  ,
The energy of , Drosophila , to comprehend difficult behaviors ,
Halting is a crucial decision that almost all dog behaviors require. When foraging, an animal may stop when it detects food to eat, when ugly, it must cease to man itself. Although it seems easy, stopping capacity has not been fully understood because it involves difficult interactions with competing actions like walking.  ,
Dr. Salil Bidaye, a scientist at Max Planck in Florida, is an expert at utilizing the potent research model, Drosophila Melanogaster ( also known as the fruit fly ), to understand how neural circuit activity causes detailed and complicated behaviors like navigating through an environment.
Having recently identified cells essential for forward, back, and turning movement, Dr. Bidaye and his team turned to ending.  ,
The ability to move through the world depends on slowing in the right direction just as much as running. It is key to critical behaviors like eating, mating, and avoiding injury. We were curious to learn how the mind handles halting and , where walking signals are overridden by slowing signals, said Bidaye.  ,  ,
Taking advantage of the berry bird’s power as a research model, including the animal’s reduced nervous system, little lifespan, and big offspring numbers, Bidaye and his team used a biological screen to determine neurons that initiate stopping.
The researchers focused on smaller groups of cells to see which caused readily moving flies to quit by using optogenetics to activate certain neurons by shining a crimson light.  ,
Two methods for stopping ,
Three distinct nerve forms, named Foxglove, Bluebell, and Brake, caused the fly to halt when activated. The scientists discovered that the fly ‘ stopping systems varied depending on which nerve was engaged through careful and detailed analysis.
Foxglove and Bluebell cells inhibited ahead walking and turning, both, while Brake cells overrode all walking orders and enhanced leg-joint weight.  ,
The range of expertise of our research team was crucial for studying detailed stopping mechanisms. Each staff member contributed to our understanding by approaching the issue through different methods, including foot motion analysis, imaging of neurological action, and mathematical modeling”, credits Bidaye.
” More, significant study collaborations spanning several labs and countries have recently identified the connections between all the cells in the travel brain and nerve cable. Our research and understanding of the neural circuitry and halting mechanisms were guided by these wiring diagrams.
The research team, consisting of scientists from Max Planck Florida, Florida Atlantic University, University of Cambridge, University of California, Berkeley , and the MRC Laboratory of Molecular Biology, combined the data from the wiring diagrams and these multiple approaches to gain a holistic understanding of the behavioral, muscular, and neuronal mechanisms that induced the fly’s halting.
They discovered that by activating these various neurons, the flies did not work in the same way, but rather by using two distinct mechanisms, called” Walk-OFF” and” Brake.”  ,
As the name implies, the” Walk-OFF” mechanism works by turning off neurons that drive walking, similar to removing your foot from the gas pedal of a car. The Foxglove and Bluebell neurons use the inhibitory neurotransmitter GABA to sabotage the neurons that cause walking.  ,  ,
On the other hand, the” Brake” mechanism, which are carried out by the nerve-cable excitatory cholinergic brake neurons, actively stops stepping by enhancing leg joint resistance and providing postural stability.
This mechanism is comparable to pressing the brake on a car to actively prevent the wheels from turning. The” Brake” mechanism also blocks walking-promotion neurons in addition to preventing stepping, just as you would remove your foot from the gas to press the brake.  ,
Lead researcher on the project Neha Sapkal, describes the team’s excitement in discovering the” Brake” mechanism.
The fly’s” Walk-Off” mechanism was similar to stopping mechanisms found in other animal models, but the” Brake” mechanism was completely new and caused such potent stopping. We were immediately interested in understanding how and when the fly would use these different mechanisms” . ,  ,
Context-specific activation of halt mechanisms ,  ,
To determine when the fly might use the” Walk-OFF” and” Brake” mechanisms, the team again took multiple approaches, including predictive modeling based on the wiring diagram of the fly nervous system, recording the activity of halting neurons in the fly, and disrupting the mechanisms in different behavioral scenarios.  ,  ,
Their findings suggested that the two mechanisms were activated by relevant environmental cues and were mutually exclusive in various behavioral contexts.
The” Walk-OFF” mechanism is engaged in the context of feeding and activated by sugar-sensing neurons. On the other hand, the” Brake” mechanism is employed when grooming and is thought to be activated by the sensory data coming from the fly’s bristles.  ,  ,
The fly must maintain balance while lifting several legs while grooming. This stability is provided by the active resistance at the joints and increased postural stability of the standing legs, according to the Brake mechanism. Indeed, when the scientists disrupted the’ Brake ‘ mechanism, flies often tipped over during grooming attempts.  ,
” The fly brain has provided insight into how specific mechanisms of behaviors like stopping are affected by contextual information,” said the researcher.
We hope that identifying these mechanisms will help us identify context-specific processes that are similar to those found in other animals, according to Bidaye. When we stop and lift our feet to adjust our shoes or take a stone off our tread, humans are likely taking advantage of a stabilizing mechanism similar to the Brake mechanism.
The key to understanding complex behaviors is to understand context-specific neural circuits and how they interact with other sensory and motor circuits. ”  ,
Funding: This research was supported by DFG- German Research Foundation, the Carl Angus DeSantis Foundation, the Wellcome foundation and the Max Planck Florida Institute for Neuroscience. This content is only under the purview of the authors, and it does not necessarily reflect the funders ‘ official opinions.  ,
About this news about neuroscience and motor control research
Author: Lesley Colgan
Source: Max Planck Institute
Contact: Lesley Colgan – Max Planck Institute
Image: The image is credited to Neuroscience News
Original Research: Open access.
” Neural circuit mechanisms underlying context-specific halting in , Drosophila” by Salil Bidaye et al. Nature
Abstract
Neural circuit mechanisms underlying context-specific halting in , Drosophila
Walking involves coordinated, distributed motor activity across the spinal cord and the brain. A crucial component of walking control is to hold on at the right time.
The neural circuitry at the heart of the competing walking state is still unsure, despite recent advances in identifying neurons that cause halting.
Here, using connectome-informed models , and functional studies, we explain two fundamental mechanisms by which , Drosophila , implement context-appropriate halting.
The first mechanism ( ‘walk-OFF’ ) relies on GABAergic neurons that block specific descending walking instructions in the brain, while the second mechanism ( ‘breath’ ) relies on excitatory cholinergic neurons in the nerve cord that cause an active arrest of stepping movements.
We demonstrate that two neurons that activate the walk-OFF mechanism cause a different population of walking-promotion neurons, causing a differentiating halt to forward walking or turning.
The brake neurons, by constrast, override all walking commands by simultaneously inhibiting descending walking-promotion neurons and increasing the resistance at the leg joints.
We identified two behavioral situations where the animal engaged in the distinct halting mechanisms in a mutually exclusive manner: the walk-OFF mechanism was engaged in the halting and stability during grooming, and the brake mechanism was in the halting and stability state.
