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A Nanoscale Look At a Complete Fly Brain (cemag.us)
An anonymous reader quotes a report from Controlled Environments Magazine: Two high-speed electron microscopes. 7,062 brain slices. 21 million images. For a team of scientists at the Howard Hughes Medical Institute's Janelia Research Campus in Ashburn, Virginia, these numbers add up to a technical first: a high-resolution digital snapshot of the adult fruit fly brain. Researchers can now trace the path of any one neuron to any other neuron throughout the whole brain, says neuroscientist Davi Bock, a group leader at Janelia who reported the work along with his colleagues on July 19 in the journal Cell.
The fruit fly brain, roughly the size of a poppy seed, contains about 100,000 neurons (humans have 100 billion). Each neuron branches into a starburst of fine wires that touch the wires of other neurons. Neurons talk to one another through these touchpoints, or synapses, forming a dense mesh of communication circuits. Scientists can view these wires and synapses with an imaging technique called serial section transmission electron microscopy. First, they infuse the fly's brain with a cocktail of heavy metals. These metals pack into cell membranes and synapses, ultimately marking the outlines of each neuron and its connections. Then the researchers hit slices of the brain with a beam of electrons, which passes through everything except the metal-loaded parts. "It's the same way that x-rays go through your body except where they hit bone," Bock explains. The resulting images expose the brain's once-hidden nooks and crannies.
The fruit fly brain, roughly the size of a poppy seed, contains about 100,000 neurons (humans have 100 billion). Each neuron branches into a starburst of fine wires that touch the wires of other neurons. Neurons talk to one another through these touchpoints, or synapses, forming a dense mesh of communication circuits. Scientists can view these wires and synapses with an imaging technique called serial section transmission electron microscopy. First, they infuse the fly's brain with a cocktail of heavy metals. These metals pack into cell membranes and synapses, ultimately marking the outlines of each neuron and its connections. Then the researchers hit slices of the brain with a beam of electrons, which passes through everything except the metal-loaded parts. "It's the same way that x-rays go through your body except where they hit bone," Bock explains. The resulting images expose the brain's once-hidden nooks and crannies.
And yet the fly adapts to so many different situations, flies,"eats", copulates etc.... that emphasizes how powerful the 3D brain structure is, and how our current AI is not.
Slashdot, fix the reply notifications... You won't get away with it...
It has about 300 neurons, 1000 cells all up (so about a third are neurons). Its connectome (wiring diagram) has been known for decades, and unlike human brains is identical in each worm. But how it actually thinks remains a mystery.
So good work to understand a fruit fly, and no doubt useful. But do not mistake it for understanding.
While understanding neurons might be helpful for building an AI, I think it is unlikely that an AI will be any direct mapping. Aeroplanes are not built out of feathers.