Nature News

Melancholy researchers rethink common swimming assessments in mice

Scientists make inferences concerning the psychological well being of a mouse by measuring the time it takes to cease swimming.Credit score: Philippe Psaila / Science Picture Library

Virtually all scientists who’ve used mice or rats to check melancholy are conversant in the compelled swimming check. The animal is thrown right into a water tank whereas researchers watch for a way lengthy it tries to remain afloat. In concept, a depressed rodent will quit sooner than a contented one – a speculation that has guided a long time of analysis on antidepressants and genetic modifications designed to induce melancholy in laboratory mice.

However psychological well being researchers have turn into more and more skeptical over the previous few years about whether or not the compelled swimming check is an efficient mannequin for melancholy in folks. It’s not clear if mice cease swimming as a result of they’re shot or as a result of they’ve discovered that a lab technician would evacuate them from the tank after they cease transferring. Components such because the temperature of the water additionally appear to have an effect on the outcomes.

"We have no idea what a melancholy appears to be like like in a mouse," says Eric Nestler, a neuroscientist at Icahn Medical Faculty on Mount Sinai in New York.

Now, the animal rights group Individuals for the Moral Remedy of Animals (PETA) is leaping into the fray. The group needs the US Nationwide Institute of Psychological Well being (NIMH) in Bethesda, Maryland, to cease supporting using the compelled swimming check and related behavioral assessments by its workers and beneficiaries of subsidies. The assessments "create intense concern, anxiousness, terror and melancholy in small animals" with out offering any helpful information, PETA mentioned in a letter to the company on July 12.

The animal rights group additionally singled out Joshua Gordon, director of the NIMH, for utilizing the compelled swimming check within the early 2000s when he was a researcher at Columbia College in New York.

"The Nationwide Institute of Psychological Well being has been discouraging for a while using some behavioral assessments, together with the compelled swim check and the tail suspension, as fashions of melancholy," mentioned Gordon in a press release to Nature. "Though many scientists don’t acknowledge the mechanistic specificity enough for a check on an animal to seize all of the complexity of a human dysfunction, these assessments are significantly helpful for clarifying the neurobiological mechanisms underlying human melancholy ".

However Gordon mentioned the assessments had been nonetheless "essential" for some particular scientific points and that the NIMH would proceed to fund such research.

Though scientists insist that behavioral assessments that trigger stress in animals are needed for the event of human remedies, the PETA market