Break through the mechanisms of thought. It’s every neuroscientist’s dream. And, as surprising as it may seem to the neophyte, the map of a fly’s brain, which researchers have just published, could well bring this dream a little closer to reality.
Alright, it’s just a fly. A fly larva, too. But all the same. For neuroscience, this is a historic achievement. Because scientists see the brain of flies as a model of brainbrain comparable to ours. And some researchers from Johns Hopkins University (USA) and the University of Cambridge (UK) have just published a detailed map of each of the neuronal connections of a Drosophila larva — Drosophila melanogaster, as scientists call it. What hope to finally understand the mechanisms of thought. Or at least, inspire new machine learning architectures.
Remember that until now, only partial brain maps had been produced. Or rudimentary brain maps. Numbering no more than a few hundred neuronesneurones. Today, the researchers are indeed presenting the most complete map of an insect brain ever produced: more than 3,000 neurons and no less than 548,000 connections.
From fly brain to human brain
Even with modern technologies, the operation took more than a decade. Time to cut the brain of the fly into thousands of individual tissue samples, to image them by electron microscopy – about a day per neuron – then to reconstruct the whole, neuron by neuron. Imagine what it would take to map the brain of a mouse, estimated to be a million times more complex than that of a fly…
In the meantime, the researchers observe that the most active circuits in the brain of the fly larva are those linked to the center of learning. With features strikingly reminiscent of the most powerful machine learning architectures. “What we’ve learned about how flies’ brains shape our understanding of our brains”explains Joshua Vogelstein, a biomedical engineer, in a press release from Johns Hopkins University. “That’s what we want to figure out: how to write a program that leads to a human brain network. »
What’s in a Fly’s Brain?
To the uninitiated, it looks like nothing more than a rainbow of intertwined threads. But for neurologists, this is a precious snapshot digitaldigital haute resolutionresolution of the brain of a fruit fly. A surprisingly complex brain.
Article of Nathalie MayerNathalie Mayer published on 07/25/2018
Two electron microscopes at large vitessevitesse. 7,062 brain slices. 21 million images. Scientists from theHoward Hughes Medical Institute (USA) provides us with the most detailed image of an adult female Drosophila brain today. So detailed that it makes it possible to map the circuits of the fly brain.
“These little insects are able to learn, to remember. They know how to distinguish safe places from dangerous places. They have elaborate courtship and grooming sequences”, says Davi Bock, neuroscientist. Yet a fly’s brain is no more than the size of a poppy seed and contains only 100,000 neurons.
More complex than expected
The team from the Howard Hughes Medical Institute was particularly interested in a region involved in memory and learning and in neurons called olfactory neurons of throwing. According to their data, these neurons are more tightly linked than previously thought. Together with neurons called Kenyon cells and other neurons, they thus form a well-ordered structure.
“We believe that our work can help us understand how the fly associates odors with a reward or to a punishment, for example”, explains Davi Bock. And already more than 20 research groups have taken advantage of the images that his team has graciously made available to everyone in order to probe the spirit of the fly.
In short: a conference on the amazing brain of the fly
How does the fly sleep? Why is she prone toaddictionaddiction to the nicotinenicotine or thealcoholalcohol ? What is its strategy for calculating its aerial navigations? This evening, at the ESPCI in Paris, Jean-René Martin, neurobiologist, is giving a rather original conference…
Article from the editorial staff of Futura published on 12/01/2015
Member of the Functional Brain Imaging and Behavior Team, at the Alfred Fessard Institute of Neurobiology (CNRS), Jean-Rene Martin is interested in the drosophila as a model of neurobiology, with a multidisciplinary approach, from geneticgenetic to behavior.
This evening, the lecture given at the École supérieure de physiquephysique and of chemistrychemistry from Paris (ESPCI ParisTech), will present rather astonishing results of this work, as evidenced by this presentation.
How does brain activity translate into specific behaviors? Which neurons are responsible for these behaviors? The Drosophila fly is an excellent model organismmodel organism to answer such questions. During this experimental conference, Jean-René Martin will use a video system which makes it possible to analyze how fruit flies move in space and time. It will show that the fly avoids the center of a arenaarena (centrophobia), and organizes its journey in a very sophisticated way (with, for example, a fractal-type temporality). The underlying brain structures will be presented, along with their homologies to mammalian brain structures, such as place cells.
Other types of behavior will be discussed, such as sleepsleep and the ethanol addiction, nicotine or cocaine, which can also be studied in Drosophila using video recordings. In short, you will discover how a fly chooses its path, organizes its time, or even how it sleeps or why it dopedope…
Monday, January 12, 2015 at 6:30 p.m.
Langevin Amphitheater of ESPCI ParisTech
10, rue Vauquelin, 75005 Paris