Sensitivity of the Goldfish Motion Detection System Revealed by Incoherent Random Dot Stimuli: Comparison of Behavioural and Neuronal Data

Abstract

BackgroundGlobal motion detection is one of the most important abilities in the animal kingdom to navigate through a 3-dimensional environment. In the visual system of teleost fish direction-selective neurons in the pretectal area (APT) are most important for global motion detection. As in all other vertebrates these neurons are involved in the control of slow phase eye movements during gaze stabilization. In contrast to mammals cortical pathways that might influence motion detection abilities of the optokinetic system are missing in teleost fish.ResultsTo test global motion detection in goldfish we first measured the coherence threshold of random dot patterns to elicit horizontal slow phase eye movements. In addition, the coherence threshold of the optomotor response was determined by the same random dot patterns. In a second approach the coherence threshold to elicit a direction selective response in neurons of the APT was assessed from a neurometric function. Behavioural thresholds and neuronal thresholds to elicit slow phase eye movements were very similar, and ranged between 10% and 20% coherence. In contrast to these low thresholds for the optokinetic reaction and APT neurons the optomotor response could only be elicited by random dot patterns with coherences above 40%.ConclusionOur findings suggest a high sensitivity for global motion in the goldfish optokinetic system. Comparison of neuronal and behavioural thresholds implies a nearly one-to-one transformation of visual neuron performance to the visuo-motor output. In addition, we assume that the optomotor response is not mediated by the optokinetic system, but instead by other motion detection systems with higher coherence thresholds.

Motion cues tune social influence in shoaling fish

“…We tuned the coherency of these stimuli ( C :0.00, 0.33, 0.66, 1.00) by including noise in the form of distractors that moved about at random (see Methods for additional details). Coherency here reflects a signal-noise ratio similar to that used in Random Dot Motion assays (RDM) 35 , 37 , 43 , but it also provides a visual correspondence to the changes expected in a fish’s visual field as the degree of organized motion in its group ranges from disorder (random motion with no leaders, C = 0) to order (perfectly aligned with only leaders, C = 1). In the null condition there are no leader silhouettes to provide directional cues ( C = 0) and so the program randomly designates one arm over the other as the ‘correct’ choice to remain consistent with the remaining coherency levels in which leader silhouettes are present.…”

Anatomy and function of retinorecipient arborization fields in zebrafish

“…CPN neurons have small receptive fields, show no habituation, are directional in the horizontal plane, and respond best to slowly moving objects (Friedlander, 1983). Furthermore, pretectal neurons, clearly located in the goldfish CPN, are visually directional sensitive in both horizontal and vertical axes (Debowy & Baker, 2011; Masseck et al, 2010; Masseck & Hoffmann, 2009a, 2009b) and implicated in the optokinetic reflex (see also Fite, 1985). Interestingly, a band of cells interconnects the CPN with the DAO (see Figure 5b,c) and retinal projections in the common roach cover both CPN and DAO, including this interconnecting band of cells, indicating that CPN and DAO may be functionally connected as an accessory optic system (AOS; see new data in zebrafish discussed in Section 3).…”

Optocollic responses in adult barn owls (Tyto furcata)

“…For a long time, OCRs, OKRs and OMRs were studied in a broad variety of animals [e.g. flies (Borst et al 2010), crabs (Sandeman et al 1975;Nalbach 1989;Barnatan et al 2019), goldfish (Easter 1972;Masseck et al 2010), frogs (Dieringer and Precht 1982), geckos (Masseck et al 2008), turtles (Ariel 1997), pigeon (Gioanni et al 1981;Gioanni 1988;Nalbach 1992;Türke et al 1996;Maurice et al 2006), chicken (Wallman and Velez 1985), hummingbirds (Goller and Altshuler 2014;Gaede et al 2016), cat (Schweigart and Hoffmann 1988), ferret (Hupfeld et al 2007), monkeys (Cohen et al 1977;Lappe et al 1998;Distler et al 1999), and humans (van den Berg and Collewijn 1988)]. Recent work has focused on model systems like zebrafish, mouse, and healthy as well as impaired human subjects (e.g.…”