Behaviour in Ecotoxicity Testing
The nervous system of even the simplest animals’ processes and integrates the real-time multi-sensory data to make complex decisions and then actuates the defined locomotory outputs that are commonly referred to as behavioral phenotypes
These responses are the ultimate result of neuronal networking and signaling and cannot be evaluated in vitro. Behaviors are often classified as the highest levels of functional physiological organization that enables animals to react and adapt to complex and intertwined matrix of external (environmental) as well as internal (physiological) stimuli
From the perspective of ecotoxicology and chemical risk assessment behavioral endpoints have been reported as sensitive and highly integrative biomarkers of exposure to industrial pollutants even at sub-lethal concentrations of chemicals.
Behavioural phenotyping is an essential part of predictive neurotoxicology and neuro-active drug discovery. It is also emerging as distinctly advantageous to assess impact of pollutants in ecotoxicology.
From the ecotoxicological perspective, behaviour is a highly dynamic sub-lethal endpoint. Changes in behavioral traits have been also broadly linked to diminished ecological fitness during chronic exposures at environmentally relevant concentrations of pollutants.
Accordingly, there is rapidly growing interest in behavioural ecotoxicology and eco-neurotoxicology following numerous reports that diverse anthropogenic pollutants can significantly alter animal behaviour leading to long term ecological consequences.
Spontaneous locomotory activity of five test animals analysed on high-definition video using Ethovision XT 15 software.
Colour coded trajectories of five different animals in a chamber (left). Occupancy heatmap depicting region where animals spend most of the time (right) .
Chemobehavioural phenotypic analysis in ecotoxicology can be performed using diverse invertebrates such as rotifers, planarians, crustaceans, insects and molluscs. Lower vertebrates such as fish and frog tadpoles are also commonly used model species.
Computer-enabled animal tracking on digitally recorded video files is currently the gold standard in obtaining behavioural data in ecotoxicology and ethology research.
Video-based behavioural analysis usually includes several independent steps such as: (i) video recording; (ii) software-based animal tracking; and (iii) data analysis.
Video recording uses digital cameras with sensors of sufficient resolution to enable simultaneous imaging of a large area; covering multiple, uniformly illuminated test chambers (entire microwell plate or a series of Petri dishes).
Animal movement is subsequently tracked using special software algorithms in a grid of pixels on each of the individual video frames. This commonly done on the basis of pixel intensity difference between animals positioned against a contrasting background (contrast-based detection)
In our research animal tracking is performed using latest software such as Ethovision XT ver. 15 (Noldus).
High-throughput (HT) behavioural analysis strategies in ecotoxicology, neurotoxicology and Neurotox-active drug discovery.
Tracking of large number of animals in special chamber arrays performed using custom protocols on Ethovision XT 15 software
Video-based Animal Tracking
Examples of rapid and high-throughput behavioural ecotoxicity tests
High-Throughput Behavioural Analysis
Large scale, high-throughput and automated animal tracking can support prioritisation of neurotoxic chemicals and chemobehavioural screening in ecotoxicology, neurotoxicology as well as neuro-active drug discovery.
We are pioneering new behavioural analysis technologies, neurotoxicity bioassays and applications based on high-throughout video-based animal tracking.
In particular we specialise in development of advanced behavioural ecotoxicity biotests and building specialised ultra-high definition infrared video imaging systems.
At the moment we are developing systems to perform large scale taxis assays (defined directional sensorimotor responses to physical or chemical stimuli) and startle responses (alert responses to a sudden and unexpected stimulus or a simulated predator).
We have developed innovative multi-camera 4K video imaging technologies with associated video optimisation techniques as well as high-throughput animal tracking pipelines using Ethovision XT ver. 15 (Noldus) software.
At present we are developing custom real-time and online animal tracking and behavioural solutions that will support new biotests assessing impact of toxicants on cognitive (memory and learning) functions.
High-throughput and automated animal tracking provides new opportunities for chemobehavioural screening in ecotoxicology
The Neurotox Lab is pioneering innovative multi-camera 4K video imaging technologies with associated video optimisation techniques as well as high-throughput animal tracking pipelines.
Advanced Behavioural Tests
Analysis of complex behaviours using aquatic organisms is advantageous due to their sensitivity as well as high physiological and ecological relevance.
Such advanced behavioural endpoints can include diverse taxis assays (defined directional sensorimotor responses to physical or chemical stimulus), startle responses (alert responses to a sudden and unexpected stimulus or a simulated predator), conditioned place preference, new habitat exploration behaviours as well as cognitive (memory and learning) functions
Compared to simple changes in generic locomotory activities commonly applied in aquatic toxicity testing, complex behaviours require a closed-loop coordination of the sensory, temporal data processing and the actuation (locomotory) subsystems in the nervous system. Any alterations of such neuronal data processing by pollutants can have a profound connotation for survival at individual and ecosystem levels.
Advanced neuro-behavioural phenotyping in ecotoxicology
Includes sensorimotor responses to physical or chemical stimulus, startle responses (alert responses to a sudden and unexpected stimulus or a simulated predator), conditioned place preference, new habitat exploration behaviours as well as cognitive (memory and learning) functions.
Bownik A and Wlodkowic D 2021 Applications of advanced neuro-behavioural analysis strategies in aquatic ecotoxicology, Science of The Total Environment, 772, 145577 DOI
Bai Y, Henry J, Campana O, Wlodkowic D 2021 Emerging prospects of integrated bioanalytical systems in neuro-behavioral toxicology, Science of The Total Environment, 756, 143922 DOI
Henry J and Wlodkowic D 2020 High-throughput animal tracking in chemobehavioral phenotyping: Current limitations and future perspectives, Behavioural Processes, 180, 104226 DOI