Biology subjects

Anneser, L.

Publications and source records attributed to Anneser, L..

4 recordsLinked to original sources

bioRxiv2026

Open-source virtual reality platform for head-fixed adult zebrafish

Virtual realities (VRs) are powerful tools to study how brains interact with the world through behavior. We present a new platform for closed-loop high-resolution virtual-reality experiments in head-fixed adult zebrafish. The VR is defined using open-source software, projected onto a semi-hexagonal tank by three projectors, and controlled by software allowing for modular trial-and-block experimental designs. Real time VR updates are performed by an optimized algorithm based on infrared tail videos. Two-photon imaging during behavior is achieved by custom gating of VR projectors and coordinated with stimulus triggers by a microcontroller. Using this system we found that fish respond to visual landmarks in virtual corridors with distinct changes in locomotion parameters and body posture. Adding landmarks to a familiar corridor elicited localized behavioral responses that decayed with experience. Restricting the viewing distance by simulating 'murky water' further confirmed that behavioral responses were driven by the visibility of landmarks independent of their position. Our platform provides a user-friendly, versatile VR system for the joint analysis of neuronal activity and behavior in adult zebrafish

neuroscience↗

bioRxiv2023

Molecular logic of neuromodulatory systems in the zebrafish telencephalon

The function of neuronal networks is determined not only by synaptic connectivity but also by neuromodulatory systems that broadcast information via distributed connections and volume transmission. To understand the molecular constraints that organize neuromodulatory signaling in the telencephalon of adult zebrafish we used transcriptomics and additional approaches to delineate cell types, to determine their phylogenetic conservation, and to map the expression of marker genes at high granularity. The combinatorial expression of GPCRs and cell type markers indicates that all neuronal cell types are subject to modulation by multiple monoaminergic systems and distinct combinations of neuropeptides. Individual cell types were associated with multiple (typically >30) neuromodulatory signaling networks but expressed only a few diagnostic GPCRs at high levels, suggesting that different neuromodulatory systems act in combination albeit with unequal weights. These results provide a detailed map of cell types and brain areas in the zebrafish telencephalon, identify core components of neuromodulatory networks, highlight the cell type-specificity of neuropeptides and GPCRs, and begin to decipher the logic of combinatorial neuromodulation.

neuroscience↗

bioRxiv2021

The neuropeptide Pth2 modulates social behavior and anxiety in zebrafish

Animal behavior is strongly context-dependent and behavioral performance is often modulated by internal state. In particular, different social contexts can alter anxiety levels and modulate social behavior. The vertebrate-specific neuropeptide parathyroid hormone 2 (pth2) is directly regulated by the presence or absence of conspecifics in zebrafish. As its cognate receptor, the parathyroid hormone 2 receptor (pth2r), is widely expressed across the brain, we tested fish lacking the functional Pth2 peptide in several anxiety-related and social paradigms. Rodents lacking PTH2 display increased anxiety-related behavior. Here we show that the propensity to react to sudden stimuli with an escape response is increased in pth2-/- zebrafish, consistent with elevated anxiety. While overall social preference for conspecifics is maintained in pth2-/- fish until the early juvenile stage, we found that both social preference and shoaling are altered later in development. The data presented suggest that the neuropeptide Pth2 modulates several conserved behavioral features, and may thus enable the animal to react appropriately in different social contexts.

neuroscience↗

bioRxiv2021

Oxytocin receptors influence the development and maintenance of social behavior in zebrafish (Danio rerio).

Zebrafish are highly social teleost fish and an excellent model to study social behavior. The neuropeptide Oxytocin is associated different social behaviors as well as disorders resulting in social impairment like autism spectrum disorder. However, how Oxytocin receptor signaling affects the development and expression kinetics of social behavior is not known. In this study we investigated the role of the two oxytocin receptors, Oxtr and Oxtrl, in the development and maintenance of social preference and shoaling behavior in 2- to 8-week-old zebrafish. Using CRISPR/Cas9 mediated oxtr and oxtrl knock-out fish, we found that the development of social preference is accelerated if one of the Oxytocin receptors is knocked-out and that the knock-out fish reach significantly higher levels of social preference. Moreover, oxtr -/- fish showed impairments in the maintenance of social preference. Social isolation prior to testing led to impaired maintenance of social preference in both wild-type and oxtr and oxtrl knock-out fish. Knocking-out one of the Oxytocin receptors also led to increased group spacing and reduced polarization in a 20-fish shoal at 8 weeks post fertilization, but not at 4. These results show that the development and maintenance of social behavior is influenced by the Oxytocin receptors and that the effects are not just pro- or antisocial, but dependent on both the age and social context of the fish.

neuroscience↗