A novel weight lifting task for investigating effort and persistence in rats, bioRxiv, 2019-09-04
AbstractHere we present a novel effort-based task for laboratory rats the weight lifting task (WLT). Studies of effort expenditure in rodents have typically involved climbing barriers within T-mazes or operant lever pressing paradigms. These task designs have been successful for neuropharmacological and neurophysiological investigations, but both tasks involve simple action patterns prone to automatization. Furthermore, high climbing barriers present risk of injury to animals andor tethered recording equipment. In the WLT, a rat is placed in a large rectangular arena and tasked with pulling a rope 30 cm to trigger food delivery at a nearby spout; weights can be added to the rope in 45 g increments to increase the intensity of effort. As compared to lever pressing and barrier jumping, 30 cm of rope pulling is a multi-step action sequence requiring sustained effort. The actions are carried out on the single plane of the arena floor, making it safer for the animal and more suitable for tethered equipment and video tracking. A microcontroller and associated sensors enable precise timestamping of specific behaviors to synchronize with electrophysiological recordings. The rope and reward spout are spatially segregated to allow for spatial discrimination of the effort zone and the reward zone. We validated the task across five cohorts of rats (total n=35) and report consistent behavioral metrics. The WLT is well-suited for neuropharmacological andor in vivo neurophysiological investigations surrounding effortful behaviors, particularly when wanting to probe different aspects of effort expenditure (intensity vs. duration).
biorxiv animal-behavior-and-cognition 200-500-users 2019The place-cell representation of volumetric space in rats, bioRxiv, 2019-07-12
AbstractPlace cells are spatially modulated neurons found in the hippocampus that underlie spatial memory and navigation how these neurons represent 3D space is crucial for a full understanding of spatial cognition. We wirelessly recorded place cells in rats as they explored a cubic lattice climbing frame which could be aligned or tilted with respect to gravity. Place cells represented the entire volume of the mazes their activity tended to be aligned with the maze axes, and when it was more difficult for the animals to move vertically the cells represented space less accurately and less stably. These results demonstrate that even surface-dwelling animals represent 3D space and suggests there is a fundamental relationship between environment structure, gravity, movement and spatial memory.
biorxiv animal-behavior-and-cognition 0-100-users 2019Probabilistic Models of Larval Zebrafish Behavior Structure on Many Scales, bioRxiv, 2019-06-15
AbstractNervous systems have evolved to combine environmental information with internal state to select and generate adaptive behavioral sequences. To better understand these computations and their implementation in neural circuits, natural behavior must be carefully measured and quantified. Here, we collect high spatial resolution video of single zebrafish larvae swimming in a naturalistic environment and develop models of their action selection across exploration and hunting. Zebrafish larvae swim in punctuated bouts separated by longer periods of rest called interbout intervals. We take advantage of this structure by categorizing bouts into discrete types and representing their behavior as labeled sequences of bout-types emitted over time. We then construct probabilistic models – specifically, marked renewal processes – to evaluate how bout-types and interbout intervals are selected by the fish as a function of its internal hunger state, behavioral history, and the locations and properties of nearby prey. Finally, we evaluate the models by their predictive likelihood and their ability to generate realistic trajectories of virtual fish swimming through simulated environments. Our simulations capture multiple timescales of structure in larval zebrafish behavior and expose many ways in which hunger state influences their action selection to promote food seeking during hunger and safety during satiety.
biorxiv animal-behavior-and-cognition 0-100-users 2019Effectiveness of treatments for firework fears in dogs, bioRxiv, 2019-06-07
AbstractAn online questionnaire survey investigated (1) management and (2) treatment methods for firework fears in dogs employed by dog owners and their (perceived) effectiveness. A PCA on data from 1225 respondents revealed four management strategies (i.e. interventions during firework exposure) the principal components “Environmental modification” (e.g. providing a hiding place, keeping windows and blinds closed, and playing music), “FeedPlay” (providing the dog with chews, play and food during fireworks in general, as well as contingent on loud bangs), “Alternative” (use of calming neutraceuticals, pheromones, herbal products, homeopathic products, Bach flowers, and essential oils) and “Interaction” (allowing body contact, petting and talking to the dog when loud bangs occurred). To explore possible effects of these management methods on fear development, the components were correlated with a score for fear progression. Of the four components, only “FeedPlay” was statistically associated with an improvement in fear responses to fireworks. To evaluate the effectiveness of various treatment strategies, owners were asked to select from a range of options which interventions they had used and whether they considered them as effective. With prescription medication (N=202), improvements were noted by 70% of owners. While individual products were not evaluated, the reported success rates for the categories “pheromones” (N=316), “herbal products” (N=282), “neutraceuticals” (N=211), “essential oils” (N=183), “homeopathic remedies” (N=250) and “Bach flowers” (N=281) were all in the range of 27-35%, which is not higher than would be expected based on a placebo effect. 44% of respondents (N=300) deemed pressure vests as effective. Counterconditioning (providing desirable stimuli after the occurrence of noises) was the most successful training technique according to the owners (N=694), with a reported effectiveness of over 70%. Relaxation training (N=433) was reported to be almost as successful at 69%, while noise CDs (N=377) were effective in 55% of cases. Thus, counterconditioining, relaxation training and psychoactive medication appear to be the most effective strategies in the treatment of firework fears in dogs. On this basis it is recommended that ad-hoc counterconditioning and relaxation training should complement the standard behavioral technique of desensitization counterconditioning with noise recordings.Highlights<jatslist list-type=bullet><jatslist-item>An online survey on treatment options for firework fears in dogs was performed<jatslist-item><jatslist-item>Feeding or playing with dogs during fireworks was associated with fear improvement<jatslist-item><jatslist-item>Success was highest for ad-hoc counterconditioning, relaxation training and medication<jatslist-item><jatslist-item>Success was similar for pheromones, neutraceuticals and other alternative products<jatslist-item><jatslist-item>Success rates for these alternative products are consistent with a placebo effect<jatslist-item>
biorxiv animal-behavior-and-cognition 100-200-users 2019Evidence for rapid phenotypic and behavioral change in a recently established cavefish population, bioRxiv, 2019-05-28
AbstractSubstantial morphological and behavioral shifts often accompany rapid environmental change, yet, little is known about the early stages of cave colonization. Relative to surface streams, caves are extreme environments with perpetual darkness and low nutrient availability. The Mexican tetra (Astyanax mexicanus), has repeatedly colonized caves throughout Mexico, suggesting an ability to adapt to these conditions. Here, we survey for phenotypic and behavioral differences between a surface population and a cave population of A. mexicanus that has recently colonized Honey Creek Cave, Comal County, Texas, likely within the last century. We found that fish from Honey Creek Cave and fish from Honey Creek surface populations differ significantly in morphological traits including length, coloration, body condition, eye size, and dorsal fin placement. Cavefish also exhibit an increased number of superficial neuromasts relative to surface fish. Behaviorally, cavefish consume fewer worms when trials are performed in both lighted and darkened conditions. Cavefish are more aggressive than surface fish and exhibit fewer behaviors associated with stress. Further in contrast to surface fish, cavefish prefer the edges to the center of an arena and are qualitatively more likely to investigate a novel object placed in the tank. While cavefish and surface fish were wild-caught and developmental environment likely play a role in shaping these differences, our work demonstrates morphological and behavioral shifts for Texas cavefish and offers an exciting opportunity for future work to explore the genetic and environmental contributions to early cave colonization.
biorxiv animal-behavior-and-cognition 0-100-users 2019DeepFly3D A deep learning-based approach for 3D limb and appendage tracking in tethered, adult Drosophila, bioRxiv, 2019-05-20
AbstractStudying how neural circuits orchestrate limbed behaviors requires the precise measurement of the positions of each appendage in 3-dimensional (3D) space. Deep neural networks can estimate 2-dimensional (2D) pose in freely behaving and tethered animals. However, the unique challenges associated with transforming these 2D measurements into reliable and precise 3D poses have not been addressed for small animals including the fly, Drosophila melanogaster. Here we present DeepFly3D, a software that infers the 3D pose of tethered, adult Drosophila—or other animals—using multiple camera images. DeepFly3D does not require manual calibration, uses pictorial structures to automatically detect and correct pose estimation errors, and uses active learning to iteratively improve performance. We demonstrate more accurate unsupervised behavioral embedding using 3D joint angles rather than commonly used 2D pose data. Thus, DeepFly3D enables the automated acquisition of behavioral measurements at an unprecedented level of resolution for a variety of biological applications.
biorxiv animal-behavior-and-cognition 100-200-users 2019