3D Fruit Fly Desktop Application Simulates Connectome on macOS

Connectome-Driven Desktop Simulation

A new macOS application introduces a 3D fruit fly that resides on the user's desktop. This virtual fly's actions, such as walking, grooming, sleeping, and fleeing, are controlled by a live spiking simulation of a portion of the FlyWire connectome. The simulation uses 668 neurons and approximately 19,000 synaptic connections, operating at 1 kHz.

Interactive Neural Visualization

The application includes an interactive brain window displaying 23,210 neuron soma positions from FlyWire v783, with live spikes indicating neural activity. Users can stimulate specific regions of the virtual brain by clicking, observing the fly's resulting behaviors. For instance, stimulating the Giant Fiber neurons triggers an escape response, while stimulating DNg11 initiates grooming.

Realistic Behavioral Responses

The fly's escape mechanism is not pre-scripted; instead, it is driven by the simulated neural network. Approaching the cursor acts as looming input to the LC4/LPLC2 visual neurons, and the fly only flees when the Giant Fiber actually spikes. This process involves approximately 1,200 synapses of feedforward inhibition, allowing the fly to tolerate slow approaches but react to fast movements within about 4 milliseconds, mirroring the behavior of a real fruit fly.

Technical Requirements and Accessibility

The application requires macOS 13 or newer and Xcode Command Line Tools (Swift 5.9+). It operates without requesting special permissions or entitlements, as it senses cursor movements, window frames, clicks, and thermal state through permission-free methods. The fly appears on a transparent, click-through overlay, ensuring it does not interfere with mouse or keyboard input.