Search bioRxiv⌕ Search

bioRxiv · 10.1101/2021.10.18.464799

Impact of walking speed and motion adaptation on optokinetic nystagmus-like head movements in the blowfly Calliphora

Abstract

The optokinetic nystagmus is a gaze-stabilizing mechanism reducing motion blur by rapid eye rotations against the direction of visual motion, followed by slower syndirectional eye movements minimizing retinal slip speed. Flies control their gaze through head turns controlled by neck motor neurons receiving input directly, or via descending neurons, from well-characterized directional-selective interneurons sensitive to visual wide-field motion. Locomotion increases the gain and speed sensitivity of these interneurons, while visual motion adaptation in walking animals has the opposite effects. To find out whether flies perform an optokinetic nystagmus, and how it may be affected by locomotion and visual motion adaptation, we recorded head movements of blowflies on a trackball stimulated by progressive and rotational visual motion. Flies flexibly responded to rotational stimuli with optokinetic nystagmus-like head movements, independent of their locomotor state. The temporal frequency tuning of these movements, though matching that of the upstream directional-selective interneurons, was only mildly modulated by walking speed or visual motion adaptation. Our results suggest flies flexibly control their gaze to compensate for rotational wide-field motion by a mechanism similar to an optokinetic nystagmus. Surprisingly, the mechanism is less state-dependent than the response properties of directional-selective interneurons providing input to the neck motor system.

Source connections

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Longden, K. D., Schützenberger, A., Hardcastle, B. J., Krapp, H. G.. 2021-10-19. Impact of walking speed and motion adaptation on optokinetic nystagmus-like head movements in the blowfly Calliphora. https://doi.org/10.1101/2021.10.18.464799

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

Development of the Highly Sensitive Horse questionnaire to assess horses' sensory processing sensitivity

It is well established that individuals vary in how they respond to situations, but might they also perceive their environment differently? Sensory Processing Sensitivity (SPS) is a multidimensional trait describing individual variation in the perception and response to sensory, emotional, and social stimuli. While extensively studied in humans, its presence in animals remains underexplored. We investigated whether horses might exhibit a comparable trait and developed the Highly Sensitive Horse questionnaire to assess equine SPS. A 104-item questionnaire was developed and refined using data from an online survey of 121 horses. The remaining 45 items were evaluated in an independent survey of 561 horses. Exploratory and confirmatory factor analyses identified a robust two-factor, 12-item structure reflecting dimensions similar to the human SPS dimensions of: Overstimulation, describing a tendency to become overwhelmed by intense or prolonged stimuli, and Sensitivity to subtleties, describing heightened perception of subtle environmental changes. The scale showed high internal consistency, excellent intra-rater and moderate inter-rater reliability. Although eSPS was associated with established behavioural traits, including fearfulness, it also explained unique behavioural variation beyond these traits. These findings suggest that horses differ in how they perceive their environment, providing a foundation to better understand equine behaviour, and opening new avenues for comparative sensory-processing research.

animal behavior and cognition↗

Behavioral divergence across replicated predation regimes is species-specific in two sympatric poeciliid fishes

Predation is a potent driver of behavioral divergence across prey populations, yet whether shared predation regimes generate similar responses in coexisting prey species remains unclear. Species differences in reproductive and foraging traits may alter vulnerability to predators, generating species-specific responses. We compared behavior and cognition of two poeciliid fishes (Gambusia affinis and Poecilia latipinna) that differ in body size, the presence of male ornamentation, and mating tactics. We sampled both species across replicate high- and low-predation regimes and measured exploration, shyness, boldness, social motivation, and detour solve latency (N = 509). Multivariate behavior and cognition differed between predation regimes, and the magnitude of divergence varied with species but not body size. Consistent with the multivariate pattern, the more conspicuous P. latipinna exhibited higher boldness and overall lower exploration under high-predation, while high- and low-predation populations of G. affinis did not differ. These findings suggest either that the more conspicuous species experiences greater predation risk or that the less conspicuous species reduces its predation risk through alternative phenotypic responses. More broadly, species differences in reproductive phenotypes associated with sexual selection may help explain why shared predation regimes generate variable patterns of behavioral divergence across taxa.

animal behavior and cognition↗

Capturing the rhythm: methodological choices shape inference from circadian activity data

Abstract 1. Statistical tools and analytical decisions for analysing animal activity data are often limited and poorly justified, particularly with respect to model choice, sampling design and temporal aggregation. These shortcomings can constrain our ability to draw accurate and biologically meaningful inferences about behaviour. 2. We interrogated 24 h activity data taken from individual males and females derived from five Drosophila melanogaster populations to generate a general framework for collecting and analysing activity data that systematically compares common model classes, continuous verses fragmented sampling strategies, and alternative temporal aggregation choices (time-bin sizes). 3. Our analyses identified generalised additive mixed models (GAMMs) applied to high-frequency continuous data with small-moderate bin sizes (1-5 minutes) as providing the most robust and interpretable inference for our complex, high-frequency activity data. 4. However, our interrogation of the data set confirmed that analytical and sampling decisions need to be tailored to the study species, the timing of activities and the nature of the behaviour of interest. Accordingly, polynomial and cosinor generalised linear models, increased but biologically targeted snapshot sampling, and bin sizes smaller than one hour yielded adequate analyses with similar biological conclusions when appropriately matched to the system. 5. Our approach provides an accessible decision-making framework for activity analyses that allows researchers across behavioural, ecological and evolutionary studies to justify and optimise choices about data collection and modelling. Such an approach improves the biological relevance of inference and supporting the use of modern tracking and analytical technologies.

animal behavior and cognition↗