The most complete brain map shows every neuron of a fruit fly

Scientists were able to draw a complete map of the 10,000 brain neurons of the fruit fly. With this tool you can learn in detail how neurons are linked in animal brains.

The human brain is such an intricate organ that it will take many years to know it in detail, and a map of its functioning would be extremely helpful in uncovering some of its mysteries. Now, scientists at the Janelia Research Campus of the HHMI have taken an important step in this direction: create a high definition 3D image of the brain of a fruit fly, showing each of the 100,000 neurons in the brain. It is the most complete brain map ever created.

To achieve this, scientists took detailed pictures of the entire brain of a fruit fly from an adult female using transmission electron microscopy. Two high-speed electron microscopes were used, with which 7,062 brain slices and 21 million images were obtained. Their discoveries are published in the journal Cell.

Scientists, belonging to the Janelia Research Campus of the Howard Hughes Medical Institute in Ashburn, Virginia (USA), now can trace the path of any neuron to any other neuron throughout the brain . "Never have images of the entire brain of the fly been generated with this resolution that allows you to see the connections between neurons," says neuroscientist Davi Bock. This detail is the key to tracing brain circuits: the precise connections of the neural network that underlie the specific behavior of flies.

Despite enormous progress, we are still far from making a similar map for the 86 billion or so neurons of the human brain.

Drosophila melanogaster are surprisingly sophisticated insects: "They can learn and remember, they know which places are safe and dangerous, they have elaborate sequences of courtship and personal grooming," he says. Bock Your brain is about the size of a poppy seed and contains about 100,000 neurons (humans have 100 billion), which communicate with each other through points of contact or synapses, forming a dense network of circuits. communication

Scientists can see these cables and synapses with an imaging technique called serial transmission electron microscopy. First, they infuse the brain of the fly with a badtail of heavy metals, which Accumulate in cell membranes and synapses, and finally mark the contours of each neuron and its connections. Next, the researchers hit the slices of the brain with an electron beam that pbades through all the metal-laden parts. "It's the same way that X-rays pbad through your body except where they touch the bone," Bock explains.

The data offers a new tool for scientists to compete to map these connections. And, in a brain memory center, the data also revealed a new type of cell and other surprises. "Every time you look at images with higher resolution and more integrity, you will discover new things," says Bock.

This news was published in the magazine N + 1, Science that adds. (www.nmas1.org)