Rats seem to sigh with relief, researchers find

<body leftmargin="0" bgcolor="#000060" text="#FFFFFF" link="#FFFF00" vlink="#FF9900"> <table border="0" cellpadding="0" cellspacing="0" width="95%" height="1"> <tr> <center> <td valign="top" width="33%" height="33"> <b> <p class="MsoNormal"><font face="Arial" size="5">Rats seem to sigh with relief, researchers find</font></p> </b> <p class="MsoNormal"><font face="Arial" size="1">Posted April 11, 2005<br> Special to World Science<br> </font> <b> <font size="2" face="Arial"><br> Rats seem to sigh with relief when an expected electrical shock fails to come, researchers say.<br> <br> The researchers trained rats to expect electric shocks after hearing a tone, by repeatedly administering a shock after the tone.<br> <br> But during part of the training, the researchers also sometimes played a second tone after the first one. When that second tone was played, no shock followed, so the rats learned that the second tone meant a reprieve.<br> <br> After that second tone, rats very often took a deep breath—an act that in humans is correlated with relief, the researchers found.<br> <br> The researchers, with the Nencki Institute of Experimental Biology in Warsaw, wrote a paper on their findings that was published in the June 20 issue of the research journal Physiology & Behavior.<br> <br> A deep breath, or a sigh, is a common action in many mammals that works to prevent provide extra air to under-ventilated parts of the lungs, the researchers wrote.<br> <br> “Sighs are also correlated with emotions,” wrote the researchers, Stefan Soltysik and Piotr Jelen. In humans, these emotions include anxiety, anger and resentment “and obviously, judging from the expression—sigh of relief—in many languages, with relaxation or relief.”<br> <br> If sighs can be shown to occur particularly often in conjunction with a particular mood, this might mean it serves a signal of that mood, they added. <br> <br> The researchers found that rats sighed more than 7 times as often during the situation of relief, after the second shock, than during a stuation of fear. They also sighed 20 times as often during relief as between trials, they added.<br> <br> “This clear correlation of sighs with relief (from fear of the tail shock) supports our hypothesis that sighs in social mammals may function as signals of safety,” they wrote.* * * </font> </p> </b> <p><b><font face="Arial" size="2" color="#FFFFFF">Send us a <a href="mailto:editor@world-science.net">comment</a> on this story, or <a href="mailto:?Body=http://www.world-science.net/exclusives/050726_ratrelieffrm.htm">send it to a friend</a></font></b> </p> <p>  </center> </td> </tr> </table> </body>