Norwegian, Belgian and British scientists are embarking on a new project to determine whether or not cod are able to feel pain. Although fish show many signs of being able to experience the sensation, very little is known about how their brains react to potentially painful stimuli. Now, the researchers will use the latest in medical technology to probe the inner workings of the cod brain. 'Most people agree that mammals and birds can feel pain, but people are less sure about fish,' said the project leader Øyvind Aas-Hansen of NOFIMA, an aquaculture research institute whose headquarters are in Tromsø, Norway. 'Not much is known about how the brain works in fish.' Some scientists argue that the fish brain lacks the structures needed to process pain. Nevertheless, fish show many of the signs associated with the ability to suffer in this way. These include behavioural responses (such as avoidance reactions and rubbing the affected part of the body), the ability to produce pain-relieving opiates, and the presence of physical structures such as pain receptors and opiate receptors. The aim of this project is to identify which parts of the cod brain are activated when the fish are exposed to potentially painful stimuli, and examine how these signals are processed. The researchers will use functional magnetic resonance imaging (fMRI) and electroencephalograms (EEGs), among other things, to see inside the cod brain. 'This is ground-breaking work,' commented Dr Aas-Hansen. 'No other scientists have previously studied the cod's brain this way.' Dr Aas-Hansen is keen to emphasise the fact that the fish will not be tortured during the experiments. 'We will use the same procedures as those used on healthy human volunteers,' he told CORDIS News. This means that the pain stimuli will be kept to a low level so that they only provoke an unpleasant sensation, not severe pain, the scientist explains. The results of this project are unlikely to affect legislation, as most regulations already take a precautionary approach to the issue and assume that fish can feel pain. However, Dr Aas-Hansen hopes that the findings will add to the arguments in favour of keeping fish in humane conditions. Furthermore, he adds, 'Comparative research on how the brain works in different animals can give an insight into our brain.' The project, which is funded by the Norwegian Research Council, will run for three years.