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.

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 September 19, 2014 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 September 19, 2014).

Share This



More Plants & Animals News

Friday, September 19, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Elephant Undergoes Surgery in Tbilisi Zoo

Raw: Elephant Undergoes Surgery in Tbilisi Zoo

AP (Sep. 18, 2014) Grand the elephant has successfully undergone surgery to remove a portion of infected tusk at Tbilisi Zoo in Georgia. British veterinary surgeons used an electric drill to extract the infected piece. (Sept. 18) Video provided by AP
Powered by NewsLook.com
Chimp Violence Study Renews Debate On Why They Kill

Chimp Violence Study Renews Debate On Why They Kill

Newsy (Sep. 17, 2014) The study weighs in on a debate over whether chimps are naturally violent or become that way due to human interference in the environment. Video provided by Newsy
Powered by NewsLook.com
Some Tobacco Farmers Thrive Amid Challenges

Some Tobacco Farmers Thrive Amid Challenges

AP (Sep. 16, 2014) The South's tobacco country is surviving, and even thriving in some cases, as demand overseas keeps growers in the fields of one of America's oldest cash crops. (Sept. 16) Video provided by AP
Powered by NewsLook.com
Scientists Given Rare Glimpse of 350-Kilo Colossal Squid

Scientists Given Rare Glimpse of 350-Kilo Colossal Squid

AFP (Sep. 16, 2014) Scientists say a female colossal squid weighing an estimated 350 kilograms (770 lbs) and thought to be only the second intact specimen ever found was carrying eggs when discovered in the Antarctic. Duration: 00:47 Video provided by AFP
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:
from the past week

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