Biology subjects

Arrenberg, A. B.

Publications and source records attributed to Arrenberg, A. B..

11 recordsLinked to original sources

bioRxiv2026

Electrical Stunning does not affect Brain Tissue Integrity and Stress Response in Larval Zebrafish

Electrical stunning is a humane euthanasia method for larval zebrafish, and a suitable euthanasia protocol has recently been established. Here, we assess the associated stress response and tissue integrity. When compared to MS-222 overdose and hypothermia, electrical stunning caused no significant Hsp70 increase. Brain tissue was preserved and muscle tissue affected only slightly. Our results support the suitability of electrical stunning for humane euthanasia and artifact-free post-mortem analyses.

systems biology↗

bioRxiv2026

MARINER: a surround visual stimulator for vision research in aquatic animals

Aquatic vertebrates are increasingly used in neuroscience research, yet underwater visual stimulation remains a challenge. Commonly used monochromatic stimuli have been shown to be inadequate to activate many visual neurons properly, and underwater refraction artifacts are prone to ruin stimulus designs. Here, we present MARINER - a visual stimulator, which remedies these issues and integrates concurrent behavioral and neurophysiological two-photon calcium imaging recordings. MARINERs full-field visual stimulation combined with receptive field mapping reveals that the visual field of larval zebrafish is larger than previously thought, extending almost down below the fish, and is spatially biased to better utilize motion content in naturalistic visual scenes. Using chromatic motion nulling, we further show that behavioral responses and task-associated sensory neurons are colorblind for "red" and "green" during the larvas optokinetic response. The MARINER stimulator facilitates naturalistic stimulation and faithful presentation of colored visual underwater stimuli for small aquatic species.

neuroscience↗

bioRxiv2025

Species-specific oculomotor control tolerances predict saccadic suppression strength in macaques and zebrafish

Active sensing necessarily requires integrating information about both self-generated movements as well as past, present, and future afferent inputs. However, such information is inherently variable and relies, at least in part, on uncertain extrapolations. Here, using saccadic suppression of visual sensitivity as a classic example of sensory-motor integration, we show that suppression strength in two drastically different species, macaque monkeys and zebrafish larvae, may be a direct outcome of efficient state estimation in the presence of uncontrollable sensory and motor variability. Bayesian estimator models suggest that optimal saccadic suppression should rely not just on the sensory-motor information being processed, but also on the time-dependent magnitude of unexplained variability in the nervous system encoding it. In both macaques and zebrafish larvae, and using matching visual stimulation regimes optimized for each species receptive field properties, we experimentally measured saccadic suppression strength in the superior colliculus (SC) of the monkeys and the homologous optic tectum (OT) of the fish. We also experimentally quantified additive and multiplicative motor noise components in the oculomotor behavior of both species, and we furthermore estimated noise in the sensory systems. We found that inter-species differences in sensory and motor noise levels and their theoretically predicted impacts on visual sensitivity are consistent with our experimentally observed differences in saccadic suppression strength between the fish and the monkeys. Because sensory and motor noise levels can reflect the amounts of available neural resources committed to a given task, our results strongly underscore the value of incorporating computational resource limits into investigating performance differences that have evolved in homologous brain areas.

neuroscience↗

bioRxiv2025

Injury-induced electrochemical coupling triggers regenerative cell proliferation

Organ injury triggers non-neuronal electric currents essential for regeneration. Yet, the mechanisms by which electrical signals are generated, sensed and transmitted upon damage to promote organ growth remain unclear. Here, we uncover that organ regeneration relies on dynamic electrochemical coupling between tissue-wide depolarization and intracellular proliferative signalling. By sub-second live imaging of injured zebrafish larval fins, we identify events across timescales: a millisecond tissue depolarization gradient, followed by seconds-persistent intracellular Calcium responses. Subsequently within one hour, Voltage Sensing Phosphatase activity translates depolarisation into proliferation. Connecting these timescales with an electro-diffusive model showed that ionic fluxes and electric potential become coupled in the fins interstitial space, enabling organ-wide signal spreading. Our work reveals the coupling between fast electrical signals and slower intracellular signalling, ensuring organ regeneration.

biophysics↗

bioRxiv2025

Vertical Optokinetic Eye Movements in the Larval Zebrafish

The optokinetic response (OKR), a reflex enabling stable visual processing by minimizing retinal slip, has been well characterized in teleosts over the last decades. While previous work on teleost OKR mostly focused on its horizontal component, mammals are known to perform vertical and torsional OKR in addition to horizontal OKR. In this study, we characterize the vertical optokinetic response (vOKR) in larval zebrafish and compare it to the horizontal OKR (hOKR) and the vertical vestibulo-ocular reflex (vVOR). Our simultaneous camera-based tracking of vertical and horizontal eye positions reveals a distinct vOKR in larval zebrafish, but with a much smaller dynamic range compared to the hOKR and without any quick phases (resetting saccades). When presented with constant roll-rotating visual stimuli, zebrafish exhibit a brief initial vertical eye rotation in the direction of the stimulus, followed by a period without further slow phase response and interspersed with only spontaneous saccades. This behavior contrasts sharply with the periodical occurrence of resetting saccades (quick phases) during hOKR. The initial vertical response is tuned to similar spatial frequencies and angular velocities as the hOKR. We furthermore show that the vVOR has a much larger vertical dynamic range than the vOKR, demonstrating that the neuronal circuitry itself - and not the oculomotor plant - is the limiting factor. While it is unclear whether the observed differences in vertical versus horizontal optokinetic control have an adaptive value for zebrafish, the identified differences are drastic and informative for further studies on visuomotor circuits in teleosts. Summary StatementThis study characterizes the vertical optokinetic response (vOKR) in larval zebrafish, revealing differences from the horizontal OKR and providing insights into visual processing and eye movement control.

neuroscience↗

bioRxiv2025

Saccadic Suppression Enhances Saliency of Prey-Like Stimuli in the Optic Tectum

Saccadic suppression, a reduction in visual sensitivity around the time of rapid eye movements, is well-documented in primate psychophysics but its mechanisms and functions remain debated. Here, we use zebrafish to trace the origins of saccadic suppression and we demonstrate how saccadic suppression selectively enhances the visual salience of ecologically relevant stimuli. Saccadic suppression thus contributes to more than just compensation for rapid saccade-induced image shifts. We first established a behavioral correlate of saccadic suppression in larval zebrafish escape behavior. Then, using electrophysiology, we show that retinal ganglion cells jumpstart saccadic suppression in a spatial frequency dependent manner. Calcium imaging, combined with 360{degrees} visual stimulation and behavioral tracking, revealed that motor signals enhance peri-saccadic suppression strength in the optic tectum, where suppression lasts for more than 3000 ms. Notably, saccadic suppression is much weaker and more short-lived for stimuli related to hunting or escape behavior than for behaviorally less relevant global flashes. This unequal attenuation effectively increases the salience of the ecologically relevant stimuli in the optic tectum after saccades. Our results demonstrate that saccadic suppression integrates visual and motor signals to optimize sensory processing within neural constraints, and they provide insights into evolutionarily conserved visual strategies.

neuroscience↗

bioRxiv2020

Reduction of visual stimulus artifacts using a spherical tank for small, aquatic animals

Delivering appropriate stimuli remains a challenge in vision research, particularly for aquatic animals such as zebrafish. Due to the shape of the water tank and the associated optical paths of light rays, the stimulus can be subject to unwanted refraction or reflection artifacts, which may spoil the experiment and result in wrong conclusions. Here, we employ computer graphics simulations and calcium imaging in the zebrafish optic tectum to show, how a spherical glass container optically outperforms many previously used water containers, including Petri dish lids. We demonstrate that aquatic vision experiments suffering from total internal reflection artifacts at the water surface or at the flat container bottom may result in the erroneous detection of visual neurons with bipartite receptive fields and in the apparent absence of neurons selective for vertical motion. Our results and demonstrations will help aquatic vision neuroscientists on optimizing their stimulation setups.

neuroscience↗

bioRxiv2019

Recruitment orders underlying binocular coordination of eye position and velocity in the larval zebrafish hindbrain

BackgroundThe oculomotor integrator (OI) in the vertebrate hindbrain transforms eye velocity input into persistent position coding output, which plays a crucial role in retinal image stability. For a mechanistic understanding of the integrator function and eye position control, knowledge about the tuning of the OI and other oculomotor nuclei is needed. Zebrafish are increasingly used to study integrator function and sensorimotor circuits, yet the precise neuronal tuning to motor variables remains uncharacterized.\n\nResultsHere, we recorded cellular calcium signals while evoking monocular and binocular optokinetic eye movements at different slow-phase eye velocities. Our analysis reveals the anatomical distributions of motoneurons and internuclear neurons in the nucleus abducens as well as those of oculomotor neurons in caudally adjacent hindbrain volumes. Each neuron is tuned to eye position and/or velocity to variable extents and is only activated after surpassing particular eye position and velocity thresholds. While the abducens (rhombomeres 5/6) mainly codes for eye position, in rhombomeres 7/8 a velocity-to-position coding gradient exists along the rostro-caudal axis, which likely corresponds to the velocity and position storage mechanisms. Position encoding neurons are recruited at eye position thresholds distributed across the behavioral dynamic range, while velocity encoding neurons have more centered firing thresholds for velocity. In the abducens, neurons coding exclusively for one eye intermingle with neurons coding for both eyes. Many of these binocular neurons are preferentially active during conjugate eye movements, which represents a functional diversification in the final common motor pathway.\n\nConclusionsWe localized and functionally characterized the repertoire of oculomotor neurons in the zebrafish hindbrain. Our findings provide evidence for a mixed but task-specific binocular code and suggest that generation of persistent activity is organized along the rostro-caudal axis in the hindbrain.

neuroscience↗

bioRxiv2019

Spherical arena reveals optokinetic response tuning to stimulus location, size and frequency across entire visual field of larval zebrafish

Many animals have large visual fields, and sensory circuits may sample those regions of visual space most relevant to behaviours such as gaze stabilisation and hunting. Despite this, relatively small displays are often used in vision neuroscience. To sample stimulus locations across most of the visual field, we built a spherical stimulus arena with 14,848 independently controllable LEDs, measured the optokinetic response gain of immobilised zebrafish larvae, and related behaviour to previously published retinal photoreceptor densities. We measured tuning to steradian stimulus size and spatial frequency, and show it to be independent of visual field position. However, zebrafish react most strongly and consistently to lateral, nearly equatorial stimuli, consistent with previously reported higher spatial densities in the central retina of red, green and blue photoreceptors. Upside-down experiments suggest further extra-retinal processing. Our results demonstrate that motion vision circuits in zebrafish are anisotropic, and preferentially monitor areas with putative behavioural relevance. Author summaryThe visual system of larval zebrafish mirrors many features present in the visual system of other vertebrates, including its ability to mediate optomotor and optokinetic behaviour. Although the presence of such behaviours and some of the underlying neural correlates have been firmly established, previous experiments did not consider the large visual field of zebrafish, which covers more than 160{degrees} for each eye. Given that different parts of the visual field likely carry unequal amount of behaviourally relevant information for the animal, this raises the question whether optic flow is integrated across the entire visual field or just parts of it, and how this shapes behaviour such as the optokinetic response. We constructed a spherical LED arena to present visual stimuli almost anywhere across their visual field, while tracking horizontal eye movements. By displaying moving gratings on this LED arena, we demonstrate that the optokinetic response, one of the most prominent visually induced behaviours of zebrafish, indeed strongly depends on stimulus location and stimulus size, as well as on other parameters such as the spatial and temporal frequency of the gratings. This location dependence is consistent with areas of high retinal photoreceptor densities, though evidence suggests further extraretinal processing.

neuroscience↗

bioRxiv2019

Parallel channels for motion feature extraction in the pretectum and tectum of larval zebrafish

Non-cortical visual areas in vertebrate brains extract different stimulus features, such as motion, object size and location, to support behavioural tasks. The optic tectum and pretectum, two primary visual areas, are thought to fulfil complementary biological functions in zebrafish to support prey capture and optomotor stabilisation behaviour. However, the adaptations of these brain areas to behaviourally relevant stimulus statistics are unknown. Here, we used calcium imaging to characterize the receptive fields of 1,926 motion-sensitive neurons in diencephalon and midbrain. We show that many caudal pretectal neurons have large receptive fields (RFs), whereas RFs of tectal neurons are smaller and mostly size-selective. RF centres of large-size RF neurons in the pretectum are predominantly located in the lower visual field, while tectal neurons sample the upper-nasal visual field more densely. This tectal visual field sampling matches the expected prey item locations, suggesting that the tectal magnification of the upper-nasal visual field might be an adaptation to hunting behaviour. Finally, we probed optomotor responsiveness and found that even relatively small stimuli drive optomotor swimming, if presented in the lower-temporal visual field, suggesting that the pretectum preferably samples information from this region on the ground to inform optomotor behaviour. Our characterization of the parallel processing channels for non-cortical motion feature extraction provides a basis for further investigation into the sensorimotor transformations of the zebrafish brain and its adaptations to habitat and lifestyle.

neuroscience↗

bioRxiv2017

The 100 Euro Lab: A 3-D Printable Open Source Platform For Fluorescence Microscopy, Optogenetics And Accurate Temperature Control During Behaviour Of Zebrafish, Drosophila And C. elegans

SUMMARY SUMMARY INTRO RESULTS DISCUSSION CONCLUSION METHODS AUTHOR CONTRIBUTION SUPPLEMENTARY FIGURE 1 -... SUPPLEMENTARY TABLE 1 -... SUPPLEMENTARY ASSEMBLY AND USER... SUPPLEMENTARY VIDEOS REFERENCES Small, genetically tractable species such as larval zebrafish, Drosophila or C. elegans have become key model organisms in modern neuroscience. In addition to their low maintenance costs and easy sharing of strains across labs, one key appeal is the possibility to monitor single or groups of animals in a behavioural arena while controlling the activity of select neurons using optogenetic or thermogenetic tools. However, the purchase of a commercial solution for these types of ...

neuroscience↗