Changing the conditions that zebrafish are kept in could have an impact on their behaviour in animal studies and the reliability of results, according to scientists from Queen Mary, University of London.
Zebrafish, like rats and mice, are often used by neuroscientists to explore mechanisms controlling behaviour and in the search for new compounds to treat behavioural disease such as addiction, attention deficit disorders or autism.
It is known that housing and handling affects the results of behavioural studies done in rats and mice, but until now there have been few studies of how the environment the fish are kept in before they are tested can impact on the results.
Writing in the journal PLoS ONE, Dr Caroline Brennan from Queen Mary's School of Biological and Chemical Sciences explains: "Practical considerations make zebrafish a very useful species in which to explore mechanisms controlling behaviour. Their small size (less than 2 cm) and prolific breeding (approx. 300 eggs per pairing) makes it easy and cheap to keep large numbers of zebrafish in a small space. It is also relatively easy to change the zebrafish genome to explore how changes in different genes affect behaviour.
"As fish have many proteins and brain circuits in common with humans, factors that affect the fish behaviour can tell us about things that may affect human behaviour."
One of the most commonly used zebrafish behavioural tests is the 'tank diving' test that is considered a measure of the fish's stress level. When a zebrafish is placed in a new tank it shows a characteristic 'diving' response where the fish will dive to the bottom of the tank and remain there more or less stationary for a brief period of time before rising to shallower depths. The interpretation is that the longer it takes the fish to rise, the more stressed it is. This test has been suggested as a means of screening for new compounds to treat stress disorders.
|Contact: Bridget Dempsey|
Queen Mary, University of London