Layer-Specific Targeting of Direction-Selective Neurons in the Zebrafish Optic Tectum

Abstract

Direction selectivity (DS) is an important neuronal property in the visual system, but how DS is generated beyond the retina remains controversial. Here, we report a close correspondence between the preferred direction (PD) and the morphology of DS cells in the optic tectum. Ca(2+) imaging in cells expressing the genetically encoded Ca(2+) indicator GCaMP3 and multiphoton-targeted patch-clamp recordings allowed us to compare structure and function in single neurons. The arbors of differently tuned cell types showed stereotypic differences in shape and laminar profile within the tectal neuropil. Excitatory synaptic inputs were directionally tuned and matched the PD of spike output in these cells, while inhibitory inputs were selective for nonpreferred directions. Functional Ca(2+) imaging in afferent axons showed a matching laminar distribution of DS presynaptic activity. Hence, different directions are represented in different layers, which suggests a simple mechanism for how tectal neurons acquire directional tuning in a nascent circuit.

Visually guided gradation of prey capture movements in larval zebrafish

“…This suggests a pre-calculated gradation in behavior based on the perceived distance of the prey item. There are certainly computational mechanisms that could accomplish this, such as the direction, orientation and size selectivity of tectal neurons (Del Bene et al, 2010;Gabriel et al, 2012;Grama and Engert, 2012;Niell and Smith, 2005;. How these mechanisms help calculate distance or direction of travel of paramecia is unknown.…”

The horizontal brain slice preparation: a novel approach for visualizing and recording from all layers of the tadpole tectum

“…Similarly, in zebrafish, it has been shown that the spatial pattern of visual inputs is arranged in tectal space according to the direction selectivity of the individual axons (Gabriel et al 2012). The mechanism(s) underlying how different sets of inputs are consistently guided to specific regions of the dendrite, however, is (are) not completely clear.…”

A Rotational Motion Perception Neural Network Based on Asymmetric Spatiotemporal Visual Information Processing

“…Neurophysiological studies have revealed that direction selective neurons widely exist in different animal species, including invertebrates and vertebrates, such as fly, beetle, locust, zebrafish, cat, rabbit [29], [46]- [55]. There are many ways to construct a directional selective neural network (DSNN) model [29], [31], [56].…”