Back away from a wall
Does the real wiring from LC16 to the moonwalker descending neurons turn an approaching wall into backward walking?
What we measured
- Real wiring
- backed away 22 times (0 with no wall near), bumped into the wall 0 times
- Rewired, same degrees
- backed away 14 times (0 with no wall near), bumped into the wall 7 times
- Random wiring
- backed away 69 times (69 with no wall near), bumped into the wall 0 times
- Measured with
- scripts/gym-benchmark.ts reflex: 40 s, 3 seeds each, totals
What happens
The fly walks in a square room. The wall straight ahead grows on its retina as it approaches, driving the LC16 visual projection neurons.
If the moonwalker descending neurons (MDN) fire above 40 Hz, the fly walks backwards, then turns away. Otherwise it bumps into the wall. Nothing is trained; the threshold is the only choice.
Activating LC16 makes real flies walk backwards (Wu et al. 2016), and MDN is the command for backward walking (Bidaye et al. 2014).
Inspired by: Wu et al. (2016) on LC16; Bidaye et al. (2014) on the moonwalker neurons.
How the brain is wired to the world
The mapping is part of the experiment design. Everything between senses and motor output is the connectome.
- Wall ahead, growing on the retina → LC16
- MDN above 40 Hz → walk backwards, then turn
Dataset: Subcircuit of FlyWire v783: inputs HSE, HSN, HSS, LPLC1, LC4, LPLC2, LC16, ORN_DM1, ORN_DA2, sugar/water, bitter; outputs DNa01, DNa02, DNa03, DNb05, DNa11, DNp01, MDN, DNp09, DNg13, DNp03, CB0701; paths with at least 40 synapses per step. About this dataset
Run it locally
Every experiment can also use the local runner, which simulates the brain on your own computer. It is required for connectomes too large for a browser.
git clone https://github.com/berkeyc/connectome-lab.git cd connectome-lab pip install -r local/requirements.txt python local/runner.py # listens on ws://localhost:8765
Then choose “Local runner” in the player controls and press Restart. Your browser may ask for permission to connect to a local device.