Featured Research

from universities, journals, and other organizations

Better housing conditions for zebrafish could improve research results

Date:
May 3, 2012
Source:
Queen Mary, University of London
Summary:
Zebrafish behavior and the reliability of scientific results could be impacted if the environment zebrafish live in is altered, according to scientists.

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.

Related Articles


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.

They are also a shoaling species, which means they prefer to group together. Dr Brennan and her team predicted that the environment they were kept in would affect their stress levels and, therefore, their response in the tank diving procedure.

They tested various aspects of how the fish were housed in a series of experiments. Some were kept in large groups, some in pairs; some were allowed only visual contact with other fish and some only could only smell each other.

They found that individually housed fish spent less time on the bottom of the tank compared to their group housed colleagues.

The team also studied how the fish reacted to ethanol, which is known to have an anti-anxiety effect on zebra fish. Their results showed that fish kept on their own responded to the ethanol, but those in a group did not.

In a third experiment, the team tested the levels of cortisol -- a common hormone produced when animals are under stress -- of both the group and individually housed fish, and found that individually housed fish had lower levels.

In their final experiment, they examined the effects of changing the fishes' water prior to tank diving. It had no effect on individually housed fish, but appeared to affect the typical tank diving responses of the group housed individuals.

Dr Brennan believes that the way in which the zebrafish are housed plays an important factor in obtaining reliable data from tests like this, and should be considered by researchers interested in comparative models of anxiety or indeed any behavioural test in zebrafish in order to refine their approach and increase experimental power.

She adds: "Not only will publication of our results improve the reliability of zebrafish behavioural analysis, but, by demonstrating that by refining housing one can increase the power of our analysis and reduce the number of animals used, we contribute to the 3Rs aim of UK and international science policy -- to reduce, refine and replace animals in research."


Story Source:

The above story is based on materials provided by Queen Mary, University of London. Note: Materials may be edited for content and length.


Journal Reference:

  1. Matthew O. Parker, Mollie E. Millington, Fraser J. Combe, Caroline H. Brennan. Housing Conditions Differentially Affect Physiological and Behavioural Stress Responses of Zebrafish, as well as the Response to Anxiolytics. PLoS ONE, 2012; 7 (4): e34992 DOI: 10.1371/journal.pone.0034992

Cite This Page:

Queen Mary, University of London. "Better housing conditions for zebrafish could improve research results." ScienceDaily. ScienceDaily, 3 May 2012. <www.sciencedaily.com/releases/2012/05/120503120500.htm>.
Queen Mary, University of London. (2012, May 3). Better housing conditions for zebrafish could improve research results. ScienceDaily. Retrieved January 26, 2015 from www.sciencedaily.com/releases/2012/05/120503120500.htm
Queen Mary, University of London. "Better housing conditions for zebrafish could improve research results." ScienceDaily. www.sciencedaily.com/releases/2012/05/120503120500.htm (accessed January 26, 2015).

Share This


More From ScienceDaily



More Plants & Animals News

Monday, January 26, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Florida Might Legalize Black Bear Hunting

Florida Might Legalize Black Bear Hunting

Newsy (Jan. 24, 2015) A string of black bear attacks has Florida officials considering lifting the ban on hunting the animals to control their population. Video provided by Newsy
Powered by NewsLook.com
Ebola Killing Large Portion Of Ape Population

Ebola Killing Large Portion Of Ape Population

Newsy (Jan. 23, 2015) Experts estimate Ebola has wiped out one-third of the world&apos;s gorillas and chimpanzees. Video provided by Newsy
Powered by NewsLook.com
Controversy Shrouds Captive Killer Whale in Miami

Controversy Shrouds Captive Killer Whale in Miami

Reuters - Light News Video Online (Jan. 23, 2015) Activists hope the National Oceanic and Atmospheric Agency (NOAA) will label killer whales endangered, allowing lawyers to sue a Miami aquarium to release an orca into the wild after 44 years. Jillian Kitchener reports. Video provided by Reuters
Powered by NewsLook.com
‘Healthy’ Foods That Surprisingly Pack on Pounds

‘Healthy’ Foods That Surprisingly Pack on Pounds

Buzz60 (Jan. 23, 2015) Some &apos;healthy&apos; foods are actually fattening. Fitness and nutrition expert John Basedow (@JohnBasedow) shines a light on the sneaky foods like nuts, seeds, granola, trail mix, avocados, guacamole, olive oil, peanut butter, fruit juices and salads that are good for you...but not so much for your waistline. Video provided by Buzz60
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins