Life Lines by Dr. Dolittle

Sponsored by the American Physiological Society

Archive for March 2017

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Zebra finches reward themselves for singing well

Dopamine is an important hormone released from neurons involved in reward pathways. Researchers at Cornell University wanted to know if dopamine signaling was involved in how birds learn songs. Their findings, recently published in Science, present evidence that neurons in the brain of zebra finches do in fact decrease dopamine signals when the birds hear an error in their song in comparison to when they sing ‘correctly’. The researchers also found […]

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Secrets to Longevity

A new article published in Physiological Reviews compared some remarkable similarities and differences between naked mole rats and humans. Both are relatively long-lived, highly social and have low natural selection pressures. But, this is about all they have in common. While humans are prone to developing age-related cancer, diabetes, heart disease and dementias, naked mole rats are rather resistant to these diseases. Instead, naked mole rats appear to maintain a youthful […]

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What do frogs and humans have in common?

Leptin is a hormone that signals the brain to suppress appetite in humans. While researchers at the University of Michigan described a similar appetite regulating role for leptin in South African clawed frogs (Xenopus), they also discovered that leptin signals limb development in tadpoles. They suspect that this happens once there are sufficient energy stores to begin the process of metamorphosis. Shalitin and Kiess (2017) also described a role for leptin in skeletal development of children and researchers implicate leptin in […]

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Need pest control, get a spider

A new study shows that globally, spiders consume 400-800 million tons of prey each year. That’s roughly more than double the amount of fish and meat that humans consume. Impressive…yet creepy at the same time. I suppose we should thank them for their pest control efforts. Sources: M Nyffeler, K Birkhofer. An estimated 400–800 million tons of prey are annually killed by the global spider community. The Science of Nature. 104: 30, 2017. […]

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Researchers discover new genes that protects water bears when they dry out

Water bears, aka tardigrades, are resilient little creatures. These microscopic animals can survive both freezing and boiling temperatures, radiation, high pressure, starvation, the vacuum of space and even desiccation. This last ability caught the attention of a team of researchers interested in how they are able to survive for years despite being completely dried out, an ability known as anhydrobiosis. Video by Daiki D. Horikawa, via YouTube. The team discovered special genes that […]

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Fluorescent frogs

A new article published in the Proceedings of the National Academy of Sciences presents the discovery of a species of frog with fluorescence. The South American polka dot tree frog, aka Hypsiboas punctatus is already rather cute under normal light. But when exposed to UV light, this frog really shines. It gets its glowing personality from fluorescent molecules, hyloin-L1, L2 and G1, found in the skin, lymph tissues, and secretions from glands. These molecules have not been found in […]

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Improved cognition in male turtles exposed to BPA during development

Bisphenol A (BPA) has earned a bad reputation as a potential endocrine disrupting chemical in several studies of developing animals. Some studies even report correlations of BPA levels with certain diseases in humans. Thus it is not surprising there are a plethora of BPA-free food containers, especially for baby food and bottles, as our most common route of exposure is through our diet. It gets there from the epoxy resin lining of some canned foods as […]

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Komodo dragons have antibacterial blood

Researchers studying komodo dragons (Varanus komodoensis) at George Mason University discovered 48 previously unknown peptides in their blood that might have antimicrobial properties. Their findings were published in the Journal of Proteome Research. For the largest lizard, these peptides may help prevent the animals from getting infections from their own saliva, which is host to at least 57 species of bacteria. With this number of bacteria, it is easy to understand why they evolved so many […]

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