Talk about an extreme animal. During the rainy season annual killifish, Austrofundulus limnaeus, lay eggs that are resistant to droughts. This is an important attribute for a fish that lives in temporary pools of water. The stress-resistant embryos within the eggs literally shut down their metabolism to survive months – possibly years without water. For many fish, exposure to air (and oxygen) can cause profound oxidative stress. Remarkably, this is […]
Do you have a stressed out cat? If so, try playing cat music, that’s right…music designed for cats. Researchers at Louisiana State University observed that music made specifically for felines can help them calm down during a visit to the vet. The special recordings (below) include cat vocalizations as well as sounds that are close to the vocal frequency of cats. The team found that cats who were exposed to […]
Animals that live at high altitude have evolved a number of physiological adaptations to deal with the low atmospheric oxygen concentrations (hypoxia). For low altitude acclimated animals, short exposures to high altitude results in activation of the sympathetic nervous system (i.e. the fight or flight response). This is a good thing because activation of this system results in more blood flow, especially to the heart and brain to help protect oxygen […]
A new study examined how our stress impacts our best friend’s mental health. The researchers studied Shetland sheepdogs, border collies and their owners and found that dogs living with people who had high levels of stress hormone (cortisol) in their hair follicles, similarly had high levels of cortisol in their fur. In contrast, canine anxiety does not appear to run off on people. That’s good news for those of us […]
In a new review article published in Physiology, Dr. Jonathon Stillman from San Francisco State University explores how populations of animals and humans may respond to increasing frequency of heat waves. According to Dr. Stillman, the past decade has produced some of the hottest years on record, resulting in the loss of human and animal life. Both the length and intensity of these heat waves are expected to increase, which […]
Birds show signs of stress resulting from sleep loss. A new study published in Physiological and Biochemical Zoology shows that zebra finches who are sleep deprived have increased expression of inflammatory genes in their fat tissues, spleen and hippocampus region of the brain along with increased levels of circulating stress hormones. The hippocampus is the region of the brain associated with long term memory formation. I wonder if sleep deprived birds are […]
A new study published in American Journal of Physiology – Regulatory, Integrative and Comparative Physiology explored the effects of modest heat stress (35°C, 95°F) on the physiology of pigs. The found that pigs exposed to heat stress ate less than those exposed to ambient temperatures. I understand. I eat less when it is hot outside too. Since skeletal muscle is such a large metabolically active tissue, things that alter muscle metabolism […]
Victor Zhang (Graduate Student working with Dr. Loren Buck at Northern Arizona University) gave an interesting talk on his research to measure stress and activity patterns in free living arctic ground squirrels. They found overall that females were less stressed than males although stress levels and activity varied during lactation. I think some human mothers can agree with those observations. Oliver Wearing (Graduate student working with Dr. Graham Scott […]
Freshwater organisms are especially vulnerable to environmental changes as they are exposed to both atmospheric changes as well as run-off from nearby cities; in particular, rising temperatures and increasing carbon dioxide levels from both natural factors (rainfall, geology, etc) as well as human influence (deforestatin, agriculture, urbanization). For example, studies of rivers around the world have found that carbon dioxide levels vary from 647 – 38,000 µatm. Higher levels are […]
Stress during late pregnancy may result in premature delivery or stillbirth. A new study of pregnant Rambouillet cross ewes, published in the American Journal of Physiology – Regulatory, Integrative and Comparative Physiology, was designed to understand why lambs succumb to stress late in pregnancy. They found that while arterial blood pressure and heart rates were normal during late gestation (final 2 weeks before birth) in fetuses from pregnant ewes with elevated stress hormones, fetal heart rate and aortic blood pressure declined on the day […]
Life Lines by Dr. Dolittle 