Life Lines by Dr. Dolittle

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Space Physiology

Tardigrades are not so tolerant after all

…at least when it comes to dealing with warming temperatures. In contrast to their reputation for being able to withstand almost any extreme environment (radiation, cold, drought, vaccuum of space), researchers at the University of Copenhagen have found that tardigrades may have an Achilles heal. They appear intolerant of sustained increases in temperature.  Study author Dr. Ricardo Neves was quoted in Science Daily, “The specimens used in this study were […]

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Rapid switches in metabolism of hibernating animals

  In a new study published in the American Journal of Physiology – Regulatory, Integrative and Comparative Physiology, researchers examined how changes in metabolism during torpor are regulated in 13-lined ground squirrels (Ictidomys tridecemlineatus). During hibernation, these animals cycle between bouts of torpor (about 2 weeks each) when their metabolism is reduced by 95% and body temperature can drop to 5degC and short states of interbout euthermia when both temperature […]

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Editor’s picks for 2018

The Editor’s Picks for 2018 have been released for the American Journal of Physiology – Regulatory, Integrative and Comparative Physiology. According to the editorial team, the focus of this journal is on “the regulation of whole organismal function that requires the interplay of multiple organ and tissue systems.” The top comparative physiology articles of 2018 included: An article by Hersh et al., who provided evidence that little skates may be useful […]

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What do hibernating animals and astronauts have in common?

Well, nothing yet…but imagine the possibilities of human spaceflight if we could put people into a form of stasis? While short term stasis-like states have been used in medical settings, the idea of putting people into stasis to allow long term space travel – without intensive physician oversight, remains a major goal of space agencies and companies like Spaceworks (above). Scientists at the Comparative Physiology meeting considered this very question, […]

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Sleep vs torpor

  I read an interesting review article published in Physiology comparing the low metabolic states of non-rapid eye movement sleep (NREM) and torpor. According to the article, all mammals experience NREM sleep patterns during which energy expenditure is decreased and body as well as brain temperatures decline. Animals that experience torpor (hummingbirds, arctic ground squirrels, some mice, bears, etc) have reduced metabolic rates and body temperatures that dip below baseline. NREM […]

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2018 Winners

I am pleased to showcase this year’s Comparative and Evolutionary Physiology Section (CEPS)  award recipients at the Experimental Biology conference. Winners received their awards at the CEPS banquet last week. In earlier posts, I introduced this year’s Dr. Dolittle Travel awardee as well as Dr. Stanley Hillman, this year’s August Krogh Distinguished Lecturer. Here are the rest of award recipients: The New Investigator Award was earned by Dr. Allyson Hindle […]

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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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