Life Lines by Dr. Dolittle

Sponsored by the American Physiological Society

Extreme Animals

Extreme Physiology: Radiation Tolerance

  Don’t let their small size fool you. Tardigrades, or ‘water bears’, are really tough animals. According to a review published in the American Scientist, these microscopic invertebrates can survive extreme variations in temperature from near absolute zero (-459 deg F) up to +302 deg F. They can also tolerate pressures that are 6 times greater than the deepest ocean, exposure to ionizing radiation (UV and x-ray) and the vacuum of space, as well as exposure to […]

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Frigatebirds and lambs

I was checking out the award-winning American Physiological Society’s I Spy Physiology blog and came across a couple of really interesting posts about animals: “If Only Birds Could Compete in the Summer Games” This post reported a study of how frigatebirds manage to sleep during flights out at sea that can last for weeks. By measuring brain activity, the research team found that the birds were capable of actual sleep, during which time both […]

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Secret to safer stem cell therapy or cure for cancer?

Researchers trying to find cures for cancer find naked mole rats rather interesting. Not only are these animals long-lived by rodent standards, they are also resistant to the development of cancer. By long-lived, we are talking up to 30 years! A team of researchers from Hokkaido University and Keio University in Japan have now isolated stem cells from the skin of naked mole rats and induced them to revert back to pluripotent stem […]

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Keeping arteries healthy, lessons from seals?

Heart rate decreases during diving in seals and other animals. Thus the ascending aorta becomes very important during diving as it helps to maintain blood pressure during prolonged dives. A new study published in the American Journal of Physiology – Regulatory, Integrative and Comparative Physiology was designed to examine the ascending aorta of hooded seals (Cystophora cristata) and the tiny blood vessels that supply nutrients to it, called the vasa vasorum. The […]

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Big-brained birds

Birds get such a bad rap when it comes to intelligence. Sure they have relatively small brains, but scientists have known they are similar to primates with respect to their cognitive abilities. New research published in the Proceedings of the National Academy of Sciences presents data showing how this apparent dichotomy is possible. They found that the brains of songbirds and parrots pack two times the number of neurons as a primate […]

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Limb regeneration in brittle stars

A new study published in Frontiers in Zoology examined the developmental process involved in regulating limb regeneration in brittle stars (Amphiura filiformis) following amputation of an arm. Limb regeneration is a multi-stage process involving initial healing and repair of the wounded site, initial growth of the limb followed by development of more complex layers of cells until ultimately the limb has been fully regenerated. Understanding this process in brittle stars may lead to […]

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Experimental Biology – Day 3

I LOVE THIS MEETING! DAY 3 included several very interesting comparative physiology sessions. Eldon Braun (University of Arizona) spoke about how birds have a unique way to prevent water loss and thereby dehydration. In mammals, the kidneys are responsible for recovering water from the urine. However when birds are well-hydrated, the urine enters the colon and moves backwards up the gastrointestinal tract to facilitate water reabsorption prior to voiding the […]

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Experimental Biology 2016 – Day 4

Still going strong…here are the highlights from several sessions held on Day 4: John Eme (California State University, San Marcos) presented data testing the effects of varying temperatures mimicking overwintering conditions on embryonic development of Lake whitefish. He found that indeed exposure to variable incubation temperatures between 2-8 deg C resulted in increased mortality. Moreover, the embryos hatched earlier and were smaller than animals exposed to constant temperatures. Nariman Hossein-Javaheri et al., (University […]

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Experimental Biology 2016 – Day 2

Today was a great day for trainees in comparative physiology! Here are some of the highlights from their sessions: Poster presentations: Alexis MacDonald et al., (Union College – Mentor Dr. Scott Kirkton) presented research showing that grasshopper skeletal muscles may use lactate for energy! Similarly, Dongying Wang et al., (Saint Louis University – Mentor Dr. Daniel Warren) also showed that skeletal muscle from painted turtles may use lactate. I guess it […]

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Flight advantages in older hummingbirds

In a new study published in The Auk, scientists report that well-fueled older tiny Ruby-throated Hummingbirds (Archilochus colubris) might be capable of non-stop flights of over 4,000 kilometers, wind conditions permitting. They made this remarkable observation while studying birds from 2010-2014 as the animals made stopovers at a wildlife refuge during their annual migration to South America. In general, older birds not only showed up at the wildlife refuge in Alabama earlier than younger birds, they also tended […]

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