LPLC2
systemVisionspeciesD. melanogaster3D view32 of 626 cellssources4
LPLC2 (lobula plate/lobula columnar, type 2) is a visual projection neuron type of the fruit fly that responds selectively to looming objects, such as an approaching predator. LPLC2 neurons provide the size signal that the giant fiber uses to trigger escape.
| Also known as | Lobula plate/lobula columnar, type 2 · Lobula plate–lobula columnar type II |
|---|---|
| Region | Lobula plate and lobula; axons end in an optic glomerulus, onto the giant fiber |
| System | Vision: eye and optic lobe |
| In the display bundle | 32 of the 626 reconstructed neurons in the site’s MaleCNS display bundle, which shows 626 of the model’s 166,700 neurons: LPLC2 32 |
What they are
Each LPLC2 neuron has a cross-shaped dendrite whose four arms ramify in the four layers of the lobula plate, where T4 and T5 cells sort motion by direction. Each arm extends along its layer’s preferred direction, so the neuron is excited by motion spreading outward from the centre of its receptive field (Klapoetke et al., 2017).
What they do
Each dendritic arm also receives local inhibition tuned to inward motion. This radial motion opponency makes LPLC2 unresponsive to related patterns such as contraction, wide-field rotation or a change in overall brightness (Klapoetke et al., 2017).
As a population, LPLC2 neurons densely cover visual space and terminate onto the giant fiber descending neurons, which drive the jump muscle motor neuron to trigger an escape takeoff (Klapoetke et al., 2017). LPLC2 provides the entire angular-size component of the giant fiber’s looming response, and LPLC2 neurons are necessary for giant-fiber-mediated escape (Ache et al., 2019). Their synapses onto downstream neurons also vary in number with position in visual space, along both the front-to-back and up-down axes (Dombrovski et al., 2023).
Behavior
Optogenetic activation of LPLC2 drives jumping (Wu et al., 2016).