title: 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.
authors.affiliation: Neural Circuits and Behavior Group, Department of Biomedical Optics, Max Planck Institute for Medical Research, Jahnstrasse 29, D-69120 Heidelberg, Germany.
authors.forename: Jens P
authors.initials: JP
authors.lastname: Gabriel
authors.forename: Chintan A
authors.initials: CA
authors.lastname: Trivedi
authors.forename: Colette M
authors.initials: CM
authors.lastname: Maurer
authors.forename: Soojin
authors.initials: S
authors.lastname: Ryu
authors.forename: Johann H
authors.initials: JH
authors.lastname: Bollmann
mesh_terms: D000818:Animals; D048430:Cell Shape; D009039:Motion Perception / Q000502:physiology*; D009433:Neural Inhibition / Q000502:physiology*; D009474:Neurons / Q000145:classification / Q000166:cytology* / Q000502:physiology; D018408:Patch-Clamp Techniques; D013477:Superior Colliculi / Q000166:cytology* / Q000502:physiology; D014795:Visual Pathways / Q000166:cytology* / Q000502:physiology; D015027:Zebrafish