3 Minute 3Rs podcast: November 2022 transcript

[NC3Rs]

It’s the third Thursday of November, and you’re listening to 3 Minute 3Rs, your monthly recap of efforts to replace, reduce and refine the use of animals in research. This month we’re kicking things off with a systematic review exploring the application of behavioral and grimace scale parameters for post-surgical pain 

[Lab Animal] 

Minimizing pain in laboratory animals undergoing painful procedures is an ethical imperative and requires accurate detection and assessment of pain. Recognizing pain can be challenging with laboratory rodents, as prey species tend to hide signs of pain and suffering. 

There is no one "gold standard” method to measure pain in animals, and several scoring methods based on facial expressions or behaviours have been implemented for laboratory mice and rats. In a new systematic review, the current evidence base for using grimace scales, burrowing and nest building to assess post-surgical pain in mice and rats was analysed to determine the robustness and accuracy of these parameters.  

Studies consistently showed surgery and subsequent analgesia could be seen to affect grimace scale parameters but the number of papers assessing burrowing and nest building was too low to draw conclusions about the sensitivity and robustness of using these behaviours for post-surgical pain assessment. 

To learn more about this study, read the full paper in Frontiers in Veterinary Science.    

[NC3Rs]

Next, a new tool to enable more researchers to glean the benefits of systematic reviews 

[NA3RsC] 

Systematic reviews and meta-analyses of preclinical animal studies can provide scientists with a good overview of the current evidence, potential generalizability of results, and estimates of bias and validity. In turn, these findings can guide future research and evidence-based medicine. However, preclinical systematic reviews are resource intensive to conduct and can often be out of date by the time they are complete. 

But now, for preclinical models of depression and Alzheimer's disease, researchers from University of Edinburgh have developed automation tools for living systematic reviews. These tools automatically fetch relevant records, sort for inclusion, assess reporting quality, and collect important methodology and outcome metrics. These results feed into interactive web applications for literature visualization, dataset examination, and downloading of relevant citations.  

Learn more about this important resource in BMJ Evidence-Based Medicine. 

[NC3Rs]

And finally, an in vitro model providing insights into focalised hypoxia in the brain. 

Small-scale neuronal infarcts, which occur deep within the brain, have been linked to cognitive decline in neurodegenerative diseases. Despite the well-documented consequences of these acute hypoxic episodes, existing in vitro models currently fail to accurately recapitulate the effects of these transient, highly localised events. 

Last month in Frontiers in Cell and Developmental Biology, Wong et al. described how they used electrochemical localised oxygen scavenging to apply acute focal hypoxia to the axons of neuroepithelial stem cells. Their custom-made oxygen scavenging electrode allowed for transient and localised induction of hypoxia. Rates of cell death were comparable with lacunar infarcts in the human brain demonstrating the system is better able to model small white matter lesions associated with diseases such as Alzheimer’s. 

This novel in vitro system could provide crucial insight into focal hypoxia-related mechanisms, potentially offering new therapeutic targets for neurodegenerative diseases without the use of animal models. Follow the link in the description to find out more. 

That’s it for this month’s episode. 3 Minute 3Rs is brought to you each month by Lab Animal, the North American 3Rs Collaborative, and the NC3Rs. Thanks for listening, and don’t forget to listen in April for more 3Rs research.