Life Lines by Dr. Dolittle

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Tag Archive for ‘stress’

High altitude deer mice have less stress?

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 […]

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Chronic stress impacts everyone around us

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 […]

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Adapting to rising temperatures

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 […]

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Lack of sleep stresses out birds too

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 […]

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Porcine adaptation to heat stress

  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 […]

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How Animals Deal with Stress

  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 […]

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New study shows mussels are “hot and bothered”

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 […]

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