Meeting Abstract
Assessing how sensory systems respond to complex stimuli is important to understanding how animals initiate and modify diverse behaviors. In the flow-sensitive lateral line system of fishes, clusters of hair cells called neuromasts lie on top of the skin and deflect to the slightest flow. Previous work has measured the responses of lateral line afferent neurons to simple sine wave deflections of individual neuromasts. However, natural stimuli are more complex and can elicit non-linear responses. To address this, we measured the responses of afferent neurons to a mechanical white noise stimulus applied to a single neuromast. This approach deflects the neuromast with different displacements, velocities, and accelerations randomly through time. Using 4-6 day post fertilization wild-type zebrafish larvae (n = 20), we simultaneously stimulated a single neuromast, video-tracked its deflection, and made extracellular recordings of the connected afferent neuron. Preliminary results show that the elicited afferent spikes are reproducible. When a neuromast was stimulated with a 10 second train of white noise, we found that 75% of the spiking pattern from the afferent neuron was reproduced across all repeated trials (n = 19). The timing of these spikes was reliable, exhibiting a mean jitter of less than 1 ms (0.6±0.1 ms = mean±1 SD). When we compared the motion of the neuromast that immediately preceded each spike, we found considerable variation, indicating that the time history of deflection and spiking are critical to afferent firing. On-going analyses focus on identifying the components of the stimulus that are most important to the afferent neuron.
