VISION | Optic Tectum

Northmore, D.P.M.

doi:10.1016/b978-0-12-374553-8.00093-9

Cited by 59 publications

(49 citation statements)

References 13 publications

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“…The torus longitudinalis (TL) is a paired elongated neural structure lying along the medial margins of the optic tectum, suspended from the intertectal commissure and protruding into the tectal ventricle (Ito, 1971;Wullimann, 1994;Northmore, 2011). Discovered by Carus in 1814, the TL was first thought considered to be homologous to the mammalian fornix until Rabl-Rückhard (1884) showed that the TL is a structure exclusive to fish, in particular, the ray-finned fishes: chondrosteans, holosteans and teleosts (for a review of the early history of the TL, see Sargent, 1903).…”

Section: Introductionmentioning

confidence: 99%

“…Moreover, electrophysiological studies confirmed the existence of a precisely ordered topographical loop between dorsomedial TL and optic tectum. This topographical mapping over-represents the visual horizon, and is transmitted with some delay from the TL via the marginal fibers over the tectum (Northmore, 2011). Based on the photometric response, it had been suggested that the TL may play a role in the dorsal light reflex, which orients the back of the fish body toward the brighter light source (Gibbs and Northmore, 1996).…”

Section: Introductionmentioning

confidence: 99%

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Anatomy and Connectivity of the Torus Longitudinalis of the Adult Zebrafish

Folgueira

Riva-Mendoza

Ferreño-Galmán

et al. 2020

Front. Neural Circuits

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This study describes the cytoarchitecture of the torus longitudinalis (TL) in adult zebrafish by using light and electron microscopy, as well as its main connections as revealed by DiI tract tracing. In addition, by using high resolution confocal imaging followed by digital tracing, we describe the morphology of tectal pyramidal cells (type I cells) that are GFP positive in the transgenic line Tg(1.4dlx5a-dlx6a:GFP) ot1 . The TL consists of numerous small and medium-sized neurons located in a longitudinal eminence attached to the medial optic tectum. A small proportion of these neurons are GABAergic. The neuropil shows three types of synaptic terminals and numerous dendrites. Tracing experiments revealed that the main efference of the TL is formed of parallel-like fibers that course within the marginal layer of the optic tectum. A toral projection to the thalamic nucleus rostrolateralis is also observed. Afferents to the TL come from visual and cerebellum-related nuclei in the pretectum, namely the central, intercalated and the paracommissural pretectal nuclei, as well as from the subvalvular nucleus in the isthmus. Additional afferents to the TL may come from the cerebellum but their origins could not be confirmed. The tectal afferent projection to the TL originates from cells similar to the type X cells described in other cyprinids. Tectal pyramidal neurons show round or piriform cell bodies, with spiny apical dendritic trees in the marginal layer. This anatomical study provides a basis for future functional and developmental studies focused on this cerebellum-like circuit in zebrafish.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Anatomy and Connectivity of the Torus Longitudinalis of the Adult Zebrafish

Folgueira

Riva-Mendoza

Ferreño-Galmán

et al. 2020

Front. Neural Circuits

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“…Oculomotor function, used in different modes of behavior, has been maintained in TO throughout the process evolution (Kardamakis, Saitoh, & Grillner, ). The fish TO receives 98% of axons of retinal GCs (Northmore, ). Axons of various types of GCs terminate at different sublaminae of stratum fibrosum et griseum superficiale (SFGS) in a retinotopic order.…”

Section: Introductionmentioning

confidence: 99%

On the organization of receptive fields of retinal spot detectors projecting to the fish tectum: Analogies with the local edge detectors in frogs and mammals

Maximova

Aliper

Damjanović

et al. 2019

J of Comparative Neurology

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Responses of ON‐ and OFF‐ganglion cells (GCs) were recorded extracellularly from their axon terminals in the medial sublamina of tectal retino‐recipient layer of immobilized cyprinid fish (goldfish and carp). These units were recorded deeper than direction selective (DS) ones and at the same depth where responses of orientation selective (OS) GCs were recorded. Prominent responses of these units are evoked by small contrast spots flickering within or moving across their visual field. They are not selective either to the direction of motion or to the orientation of stimuli and are not characterized by any spontaneous spike activity. We refer to these fish GCs as spot detectors (SDs) by analogy with the frog SD. Receptive fields (RFs) of SDs are organized concentrically: the excitatory center (about 4.5°) is surrounded by opponent periphery. Study of interactions in the RF has shown that inhibitory influences are generated already inside the central RF area. This fact suggests that RFs of SDs cannot be defined as homogeneous sensory zone driven by a linear mechanism of response generation. Physiological properties of fish SDs are compared with the properties of frog SDs and analogous mammalian retinal GCs—local edge detectors (LEDs). The potential role of the SDs in visually guided fish behavior is discussed.

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“…In all of these organisms the optic tectum forms the midbrain and sits in between the forebrain and cerebellum. Prey, predator, flockmate, and other detectors are found in the optic tectum in fish, birds, and toads, and also initiates or triggers the required response needed for the feature detected [30][31][32]. The trigger is passed to the deeper layers of the tectum responsible for motor functions in order to guide eye and body movement to salient environmental stimuli without the need for cortical processing [30].…”

Section: Using Fixed Action Pattern Sequence For Leader-follower Formmentioning

confidence: 99%

Bio-Inspired Vision-Based Leader-Follower Formation Flying in the Presence of Delays

Oyekan

2016

Robotics

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Flocking starlings at dusk are known for the mesmerizing and intricate shapes they generate, as well as how fluid these shapes change. They seem to do this effortlessly. Real-life vision-based flocking has not been achieved in micro-UAVs (micro Unmanned Aerial Vehicles) to date. Towards this goal, we make three contributions in this paper: (i) we used a computational approach to develop a bio-inspired architecture for vision-based Leader-Follower formation flying on two micro-UAVs. We believe that the minimal computational cost of the resulting algorithm makes it suitable for object detection and tracking during high-speed flocking; (ii) we show that provided delays in the control loop of a micro-UAV are below a critical value, Kalman filter-based estimation algorithms are not required to achieve Leader-Follower formation flying; (iii) unlike previous approaches, we do not use external observers, such as GPS signals or synchronized communication with flock members. These three contributions could be useful in achieving vision-based flocking in GPS-denied environments on computationally-limited agents.

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VISION | Optic Tectum

Cited by 59 publications

References 13 publications

Anatomy and Connectivity of the Torus Longitudinalis of the Adult Zebrafish

Anatomy and Connectivity of the Torus Longitudinalis of the Adult Zebrafish

On the organization of receptive fields of retinal spot detectors projecting to the fish tectum: Analogies with the local edge detectors in frogs and mammals

Bio-Inspired Vision-Based Leader-Follower Formation Flying in the Presence of Delays

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