Meeting Abstract

P1.71  Friday, Jan. 4  Signal transmission properties of the zebrafish larval lateral line in response to neuromast deflections LIAO, J.C.*; BALLO, A.W.; AKANYETI, O.; The Whitney Lab for Marine Bioscience, University of Florida Gainesville jliao@whitney.ufl.edu

Fishes use their lateral line system to detect flow-related information using sensory units called neuromasts. Previous studies have elucidated the frequency response of neuromasts in adult fishes, but we still understand very little about how well afferent neurons can convey this information to the hindbrain. We set out to characterize the transmission capabilities of afferent neurons in response to neuromasts deflections for zebrafish larvae. We recorded afferent spike activity using intracellular sharp electrodes while deflecting neuromasts with a piezoelectric stimulator driven by a pulse train of 1-100 Hz. We calculated the vector strength, a measure of response fidelity to a stimulus, in addition to the average spike rate. At low pulse rates (<10 Hz), afferent neurons spiked in response to each pulse (i.e. phase-locked) but also retained spontaneous activity. The overall spike rate was 13.59±1.93 Hz (mean ± standard error) and the vector strength was 0.33±0.08, where a vector strength of 1 indicates that all spikes have the same phase to a pulse stimulus. 10-30 Hz stimulation revealed a vector strength of 0.99±0.01, during which spontaneous activity disappeared. The spike rate varied from the pulse rate within ± 2%. 30-60 Hz stimulation elicited a vector strength of 0.97±0.02 and spike rate was 20% less than the pulse rate. Above 60 Hz, there was no correlation between the stimulus and spike activity. Our results indicate that the optimum pulse rate that can be transmitted without information loss is between 10-30 Hz, while pulse rates up to 60 Hz can occur with only moderate information loss.