We are one step closer to simulating a complete fruit fly with this brain map

Fruit flies are similar to humans in some ways, possessing features such as eyes, legs, nervous systems, and an affinity for fruit.

The similarities between humans and fruit flies, scientifically known as Drosophila, may be overstated. Nevertheless, fruit flies are frequently used in biological experiments because they offer insights into the workings of relatively simple animals.

A Cambridge University research team recently produced a "synapse-by-synapse map" of a larval drosophila brain, which contains 3,016 neurons and 548,000 synapses, making it ten times more complex than the brain of the last organism to have its brain mapped - a type of worm. While humans have around 86 billion neurons and countless synapses, fruit flies are a suitable model because their compact brain has thousands of neurons that can be imaged at a nanoscale. By slicing the fruit fly's brain into ultra-thin layers and using electron microscopy, the team was able to analyze feedforward and feedback pathways, multisensory integration, and cross-hemisphere interactions. Although fruit flies are not flies but rather complex creatures with a range of brain functions, studying them can teach us a great deal about animals and life.

The outcome is the appearance of a model resembling a slug donning a clown wig, although I should note that this is not an accurate representation of its appearance in real life.

Undoubtedly, there are many intriguing observations to be made about the brain's organization, such as nested recurrent loops, multisensory integration, cross-hemisphere interactions, and other exciting aspects. Nonetheless, having a complete connectome of a complex organism is a source of excitement for anyone interested in this field. With a reasonable simulation of a brain, there are a plethora of possibilities. Although earlier research has replicated individual subsystems or smaller brains, this is the most comprehensive and significant characterization to date, and as a 3D digital resource, it will undoubtedly be employed and cited throughout the discipline.

Some of these features can even be found in artificial neural networks; examining how such intricate behavior is produced by such a sparsely populated brain could "potentially inspire new machine learning architectures."

Curiously, we already possess a detailed mechanical model of an adult fly's body and movements, and while the question is apparent, the answer is no: we cannot implant this brain into that body and declare that we have simulated the entire system. Perhaps next year, though.