I have to say that the winners of this IgNobel won in my heart PURELY because of the costumes they wore to the ceremony. Yes. Costumes.

(The best image I could find, from the South China Post coverage of the story, which you can read here, photo originally via Reuters)

Because if you're going to win an IgNobel, you might as well win it dressed as a giant mouse and holding a plush heart. With CLASS. Because that's what the IgNobels are all about.

So they definitely won points for style. But while the science is indeed funny...I don't know that it's going to cause people to put opera in operating rooms soon. Let's go through it, and I'll tell you why.

Uchiyama et al. "Auditory stimulation of opera music induced prolongation of murine cardiac allograft survival and maintained generation of regulatory CD4+CD25+ cells" Journal of Cardiothoracic Surgery, 2012.*

The authors of this study were investigating the healing powers of music. Music does lots of good things for humans: relaxation, comfort, etc. There are many studies that show positive effects of music in humans on a psychological level. But can it affect physical healing?

And can it do it in mice? We all know, after all, that mice are the most severe of art critics.

So the scientists wanted to look at music in mice receiving...heart transplants. Some mice got no sound. Some got opera before the transplant.

Some got Mozart for 6 days after the transplant.

Some got Enya for 6 days after the transplant.

Other mice just got tones at different frequencies for 6 days.

(Figure 1)

Above you can see the results. The music or sound choice is in columns on the far left, how each heart did (the survival rate) of each individual mouse is second from right, and the average is on the right.

And it looks like Mozart wins hands down, with a huge increase in survival time. As for Enya...ouch. I mean, it's not bad, but reduced heart transplant survival time compared to Mozart has to be a rough artistic criticism.

They did the experiment again, this time just with opera music. The opera-listening mice showed increased survival time. When they burst the ear drums of the mice (so they could not hear the music), the effect apparently went away. They also saw changes in the immune response, with mice receiving Opera having a changed immune response, showing evidence of anti-inflammatory effects.

(Figure 3)

Above you can see measures of cell proliferation (on the left), higher in mice getting transplants. On the right are measures of cytokines. If you look at IL-10, on the top right, that's a cytokine thought to have anti-inflammatory effects. It's much higher in the opera listening mice.

The authors conclude that classical music in mice (and particularly opera) as an auditory stimulus may affect the immune system.

Perhaps it may. I have to say, though, that I'm not sure that they'll be able to replicate this effect. The groups of mice they used were VERY small (n=4-5 per group), and though the Mozart group had longer survival time, two of the mice had VERY high survival times indeed (80-ish days as opposed to an average of 7-11 in controls, and as opposed to 20 in the rest of the opera group), which might skew the data and be outliers in a larger sample. There's also an additional issue with the statistics to analyze the data. They used T-tests to analyze the cytokine and flow cytometry data...even though there were three groups in each set. I personally think they should have used the one-way ANOVA for that test, which takes into account the variance within the samples. If they had used the one-way ANOVA, I'm not sure they would have gotten such significant results (though I am not a stats specialist, and I would welcome other opinions on that). Finally, they use very different groups for the cytokine analysis than they do for other types. Where's Enya in the cytokine data?! There it's just opera, no music, or no operation. I think you need a different kind of music or sound there (probably both) as another control group.

So when it comes down to it, I'm not particularly convinced that opera can save mouse hearts. They might want to do a replication, both for science and because, if they don't, and I were Enya, I'd sue to defamation of character. There's no art critic quite like a mouse rejecting a heart transplant.

*It should be considered that, while very impressively named, the Journal of Cardiothoracic Surgery has an impact factor of 0.90.