Life Lines by Dr. Dolittle

Sponsored by the American Physiological Society

Reproduction and Development

Aging and Immortality

Have you ever heard of the ‘immortal’ jellyfish, Turritopsis dohrnii? These tiny creatures (about 4.5 mm) are aptly named for their ability to essentially live forever. According to the Natural History Museum, when these jellyfish are damaged, they can actually revert to a prior life cycle as a polyp and become an adult jellyfish (aka, medusa) all over again. This process is called transdifferentiation. Check out this video from the […]

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Early indicator of pregnancy complications

Mitochondria are organelles inside our cells that are essential for generating metabolic energy in the form of ATP. It is thought that these organelles originally came from aerobic bacteria that were ingested by the first eukaryotic cells. In fact, mitochondria have their very own DNA. Cells that have higher energy needs, like those in the brain and heart, contain more mitochondria.      When cells die, mitochondrial DNA can end up […]

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Chronic stress during pregnancy increases risk of stillbirth and preterm delivery

At the end of pregnancy, levels of the hormone oxytocin increase to stimulate parturition, or childbirth. The stress hormone cortisol is also important for normal fetal development and, like oxytocin, cortisol increases at the end of pregnancy. This may help explain why chronic stress during pregnancy increases the risk of complications such as stillbirth.   A new study published in the American Journal of Physiology – Regulatory, Integrative and Comparative […]

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Domestic zebrafish are less plastic

Zebrafish have been used in medical research since at least the 1970’s as their anatomy, physiology, as well as genetics are similar to humans. Other advantages to studying zebrafish is that they are inexpensive to raise, and they reproduce well in captivity. The ability to adjust one’s physiology in response to varying environments is called plasticity. An organism may encounter any number of environmental fluctuations (light/dark, temperatures, predation risk, noise, […]

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Grappling with gravidity

In humans, pregnancy can be an uncomfortable time as the growing fetus makes it more difficult to breathe. It can also become more difficult for the expectant mother to get around. It may be surprising to find out that grasshoppers may develop similar issues when they are ‘expecting’. In fact, a gravid grasshopper can carry an egg mass that makes up as much as 40% of their weight! Could you […]

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And a Happy New….Kidney!

Spiny mice (Acomys cahirinus) are amazing animals. For starters, they are reportedly one of the only known species to date, in addition to primates, that menstruate (McKenna et al., 2021). They are also capable of regenerating skin tissue, complete with hair follicles and blood vessels without scarring, after an injury (Siefert et al., 2012). This is an important skill for animals that escape predators by shedding their skin. Add to […]

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Featuring: Ohio Physiological Society

This week we are featuring the Ohio Physiological Society. They held their 35th annual meeting September 17-18, 2021. The Ohio Physiological Society is a chapter of the American Physiological Society that was founded in 1986 and brings together physiologists from across the state. Dr. Cynthia Beall, PhD, Distinguished University Professor and Sara Idell Pyle Professor of Anthropology as well as Co-Director of the Center for Research on Tibet at Case […]

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How infections can change milk composition

Lipopolysaccharides (LPS) are found on the outer cell membrane of Gram-negative bacteria. When these bacteria break down, the LPS can enter the body and cause inflammation and negatively impact health. They can also disrupt the blood-milk barrier and may alter the composition of milk. In a new study published in the American Journal of Physiology – Regulatory, Integrative and Comparative Physiology, researchers wanted to know whether LPS could change the […]

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High altitude survival and adaptation

Life at high altitude presents unique physiological challenges for organisms that were explored in a recent review published in the American Journal of Physiology – Regulatory, Integrative and Comparative Physiology. For placental mammals, offspring born at high altitude (>2500 m above sea level) typically weigh less at birth compared to lowland animals. Fetal growth restriction is problematic as it is associated with long-term health risks and reduced survival. It is […]

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Q&A with Dr. Jon Harrison, Meredith Johnson, and Jordan Glass

We recently interviewed Meredith Johnson (graduate student), Jordan Glass (graduate student), and Dr. Jon Harrison from the School of Life Sciences at Arizona State University about the research they presented at the 2021 annual Experimental Biology conference.   Q: You mentioned in one of your presentations that insects have an ‘unusual’ respiratory system. Can you explain how it differs from mammals?  Dr. Harrison: Insects exchange gases through blind-ended air-filled tubes called tracheae. There […]

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