Lateral line units in the amphibian brain could integrate wave curvatures.

Aquatic predators like Xenopus laevis exploit mechano-sensory lateral lines to localise prey on the water surface by its wave emissions. In terms of distance, hypothetically, the source of a concentric wave could be centrally represented based on wave curvatures: for Xenopus, we present a first sample of 98 extracellularly recorded brainstem and midbrain responses to waves with curvatures ranging from 22.2-11.1 m(-1). At the frog, concurrently, wave amplitudes and their spectral composition were kept stable. Notably, 61% of 98 units displayed curvature-dependent spike rates, suggesting that wave curvatures could support an extraction of source distances in the amphibian brain.