Use of zebrafish as a model system for studies in nociception and pain: improving our understanding of fish welfare (#826)
The use of fish models in experimentation is increasing due to the advantages they can offer over traditional rodent models. Therefore, being able to rapidly assess their health in the laboratory is not only crucial to ensure the integrity of data collection but also to improve the welfare of the experimental animals. The development of an automated intelligent monitoring software tool would be a major advance in the detection and assessment of pain in laboratory fish. Using data collected from zebrafish exposed to different pain types, such a tool can provide a means of assessing pain and allowing researchers to intervene to improve welfare. Additionally the efficacy of analgesic drugs can be determined and this approach can allow the implementation of analgesic protocols in experimentation using fish models. This would represent an important refinement in scientific studies. Replacement of adults in pain or nociceptive testing using non-protected larval forms is also possible using zebrafish at 5 days post fertilisation. Due to their small size large numbers can be screened behaviourally using tracking software during innocuous and nociceptive stimulation. Further, the efficacy of analgesics can be assessed in a high-throughput manner which is of relevance to the pharmaceutical industry. The existence of transparent, transgenic zebrafish larvae expressing neuronal markers for calcium signalling means exposure to noxious stimuli can be measured in 3D in vivo in the larval brain using light sheet microscopy. Understanding how the fish brain processes incoming noxious information is an outstanding issue in neurobiology and would yield novel information on pain processing in non-mammalian vertebrates. Overall zebrafish provide substantial advantages for nociceptive testing over rodent models.