Spatially asymmetric reorganization of inhibition establishes a motion-sensitive circuit

In the retina, highly selective wiring from inhibitory cells contributes to determine the direction-selection characteristics of an individual ganglion cell, yet how the asymmetric wiring inherent to these connections is established was unknown. Here, two independent studies using complementary techniques, including pharmacology, electrophysiology and optogenetics, find that although inhibitory inputs to both sides of the direction-selective cell are uniform early in development, by the second postnatal week, inhibitory synapses on the null side strengthen whereas those on the preferred side remain constant. These plasticity changes occur independent of neural activity, indicating that a specific developmental program is executed to produce the direction-selective circuitry in the retina.