There is nothing like a good laugh, is there? It not only feels great to laugh, it can feel great to hear other people laugh. Beyond brightening the mood, can laughter provide tangible health benefits?

Lee Berk of Loma Linda University in California has done a series of studies on laughter and its possible physiological effects. We will talk to him about his latest study, done over the course of a year with diabetic patients. (Begins at 3:50)

In this month’s Buzz in Physiology (begins at 0:51), we look at studies that provide possible explanations for:

1. Why pregnant Andean give birth to larger babies at high altitude, compared to European women
2. How certain side effects in some medical procedures may trace back to a solvent found in plastic tubing

Total Time: 9:47

You can rate the show on iTunes or leave your written comments at lifelines.tv or by calling 301 637-5634 in the U.S.

Did you know that there is a sensor in the nerve endings in the carotid artery that rapidly lowers blood pressure when stimulated? This discovery may one day allow people who are hypertensive to lower their blood pressure by using a pacemaker-like device that stimulates the nerve endings in the blood vessels.

In this edition of Life Lines, we talk to Francois Abboud, of the Carver College of Medicine at the University of Iowa whose research identified this sensor. We’ll also talk to him about his recent research looking at the genes that regulate ion channels, microscopic gates that move chemicals in and out of cells, and that play a role in the signaling between the brain and the blood vessels. In experiments with animals, Dr. Abboud and his colleagues deleted one specific ion channel and found that the animals developed high blood pressure. (Begins at 03:51)

We’ll also talk to Ann M. Schreihofer, of the Medical College of Georgia, who focuses on the role the brain plays in increasing sympathetic nervous activity, which contributes to many forms of hypertension (high blood pressure). Among the questions her research seeks to answer is why people who are obese become hypertensive.

The Schreihofer laboratory has also been looking at sleep apnea and whether it is possible to improve respiratory function as a way to reduce the sympathetic activity that leads to obesity and hypertension. (Begins at 09:43)

In the Buzz in Physiology (begins at 1:24), we have studies on:

1. resistance training and octogenarians
2. muscle atrophy during lengthy space missions
3. belly fat, inflammation and exercise

The photo in our logo is a neuron from the rostral ventral lateral medulla of the brain stem and was provided by Dr. Schreihofer.

Total running time: 16:45.

Celiac Update. Celiac disease is an uncontrolled immune response to wheat gluten and similar proteins of rye and barley. In those who have celiac disease, gluten can damage the small intestine, inhibit nutritional uptake and lead to malnutrition. Among the symptoms are diarrhea, stomach pain, fatigue, weight loss and slow growth. One study estimated that 1 in 133 people in the U.S. population have celiac disease. Many people do not know they have it, sometimes because there are no symptoms. Because celiac disease has a genetic component, there can be a much higher prevalence of the disease within families.

Three years ago, a group of Dutch researchers led by Frits Koning of the Leiden University Medical Center published a study on an enzyme that showed promise as a treatment for celiac disease. The enzyme, prolyl endoprotease, or PEP, could quickly break down gluten in the stomach before it ever reached the small intestine, where it causes damage. In this episode, we ask Frits Koning to update us on his research. To find Dr. Koning’s study on PEP, click here. (Begins at 2:45)

Buzz in Physiology. To find the full press release on mental fatigue and exercise, click here. (Begins at 0:52)

Total Time:  11:20

Have you ever had an experience like this: You and a friend start jogging together. Neither of you have been exercising much, but after a few days, your friend is easily striding along as you wheeze, gasp and hold onto your aching side. Do not feel bad about your performance; it may be your genes.

Scientists have identified about 200 genes that play a role in our body’s ability to become fitter, referred to as “adaptation to exercise.” In this episode, we talk to Mark Olfert of the University of California at San Diego and Claude Bouchard of the Pennington Biomedical Research Center. They have organized a symposium on the genetics of adaptation to exercise, to take place at the Experimental Biology conference in New Orleans in April. They will give us a flavor for the research in this field by telling us a bit about their own work. (Begins at 3:51)

In the Buzz in Physiology (Begins at 1:21) University of Illinois researchers are developing a program to train people to avoid falls. This research could be particularly valuable for the elderly, for whom falling can be an especially dangerous proposition. Read the press release here, or the study here. And a study from the University College London Medical School sheds light on why patients with cirrhosis may have a more regular heart rhythm than is normal, and why they develop hepatic encephalopathy, a neurological disorder. The body’s inflammatory response may be the common thread behind the development of these conditions. Click here for the study and here for the press release.

Lucy Brown, a neuroscientist at the Albert Einstein School of Medicine, has studied romantic love using functional magnetic resonance imaging. Dr. Brown will talk about her studies on what happens in our brains at different stages of love: falling in love, being rejected by a lover, and longterm love. To find a related study, click here.

Obstructive sleep apnea is the most commonly diagnosed condition among sleep-related breathing disorders and can lead to debilitating and sometimes fatal consequences for the 18 million Americans who have been diagnosed with the disorder. To find the related study click here or you can find the press release here. You can rate the show on iTunes or leave your written comments here or call 301 637-5634 in the U.S.

Accumulating evidence indicates that an increase in particulate air pollution is associated with an increase in heart attacks and deaths. In this episode, we’ll talk to Aruni Bhatnagar of the University of Louisville and Robert Brook of the University of Michigan about research in the relatively new field of environmental cardiology. This field examines the relationship between air pollution and heart disease. (Begins at 2:58)

Why was the man known in scientific literature only as “H.M.” so important to neuroscience? David Linden of Johns Hopkins University explains why in the wake of H.M.’s recent death. (Begins at 14:54)

The Buzz in Physiology: (Begins at 1:14)
A new study with rats could help uncover how we get hooked on sugary food. You can read the full study here.

The heart’s beat is not a simple in-and-out movement, but has a bit of a twist to it. Researchers have created images showing the connection between the configuration of the heart’s muscular layer and how the heart contracts. The study is available here. Be sure to click on the supplemental video to see how it works.

We’ll start this episode by talking about clocks, but not the type of clock that ticks away on your wall. Instead, we’ll talk about the biological clocks that tick inside us. Clifford Saper of the Beth Israel Deaconness Medical Center in Boston will explain some of the research on circadian rhythm and will share his theory about the best way to deal with the disruption of the biological clock caused by jet travel. If you’re traveling this holiday season, or anytime in the near future, give a listen. (Begins at 3:14)

Do you have a tendency to overeat during the holidays? A new study finds that exercise affects the release of two hormones that help regulate appetite, ghrelin and peptide YY. This may help explain why exercise is often, even if only briefly, associated with suppression of appetite. David Stensel of Loughborough University in the United Kingdom will talk about his study, which appears in the American Journal of Physiology-Regulatory, Integrative and Comparative Physiology. Click here for the full study and here for the press release. (Begins at 11:54)

Total Time: 20:27

Why do we feel sleepy after a big Thanksgiving meal? Is there something in the turkey? Are cranberries good for our kidneys? These are some of the questions our experts will explore. Chris I. Cheeseman of the University of Alberta will talk about tryptophan in turkey. (Begins at 3:17.) L. Lee Hamm of Tulane University School of Medicine will discuss what the research shows about cranberries and kidney health. (Begins at 8:58)

Kevin Heffernan (13:26) will talk about his study, aimed at trying to uncover why African-American men have a higher rate of hypertension than white men. The research team from the University of Illinois, Urbana Champaign, found some early signs of vascular damage in young, healthy African-American men and found that measuring central blood pressure may be a better way of identifying those at risk.

Physiology in the News: (1:25)

Reservatrol
Beta agonist drugs
Mussels

Total time: 21:13

Halloween is the theme for October, so we'll talk about sleep paralysis, a condition that has been associated with stories of demon attacks during the night. We'll talk to Allan Cheyne of the University of Waterloo in Waterloo, Canada about this spooky phenomenon. (Begins at 3:46)

We'll also talk to Alexandra Shapiro and Phillip Scarpace of the University of Florida in Gainesville about their study on fructose-induced leptin resistance and obesity. This study is a bit scary if you have a sweet tooth. The study appears in the American Journal of Physiology-Regulatory, Integrative and Comparative Physiology. Click here for the study and here for the press release. (Begins at 11:40)

Buzz in Physiology: What is a 'Halloween" gene and how did it get its name? Lawrence I. Gilbert explains. And Bret H. Goodpaster will discuss his study that found that older people who diet without exercising lose more lean muscle mass than those who exercise without dieting. The study is important because older people tend to lose muscle mass as they age, and too much muscle loss may interfere with activities of daily living. Here is a link to the press release and a link to the study. (Begins at 1:46)

Total time: (23:06)

Mice are less susceptible to the flu when they eat quercetin, a substance that occurs in fruits and vegetables. Researcher J. Mark Davis will talk about his study on stressful exercise, quercetin and the flu. Click here for the study, and here for the press release. (Begins at 3:55)

In the wake of the summer Olympics, we asked Rick Lieber, of the University of California San Diego and the VA Medical Center San Diego, if the muscles of highly trained athletes could get much stronger and whether gene therapy, which is being developed for medical applications, could be used by to enhance performance in the future. (Begins at 12:56)

The Buzz in Physiology gives a quick look at a study that finds a possible link between your genes and activity level. Click here for the press release and here for the study abstract. And we detail a study on the benefits of hydrogen sulfide gas. Click here for a link to the study abstract in the American Journal of Physiology-Heart and Circulatory Physiology and a link to the press release. We also talk to APS member Jim Hicks of the University of California Irvine about his involvement with the film, Wall-E. (Begins at 1:20)