Katrina Lopez, statewide coordinator for the WalkSafe program, shows pre-schooler Quentavius Boges how to safely cross the street at a simulated crosswalk on the Linda Ray Intervention Center’s playground.
Parents and children from the Department of Psychology’s Linda Ray Intervention Center came together recently to practice safe-street crossing at an outreach event sponsored by the University of Miami WalkSafe program. Part of the KiDZ Neuroscience Center at The Miami Project to Cure Paralysis, the program is designed to reduce the number of pediatric pedestrian injuries through the use of evidence-based educational curriculum and community outreach activities.
The Linda Ray Intervention Center’s staff had identified the need to promote safe street-crossing strategies for the families enrolled in their program. The children, who meet criteria for early intervention services, and their adult caregivers were able to practice safe crossing last month on simulated crosswalks set up on the playground and joined in arts and crafts projects about safe-walking strategies.
Biologists identify signals that drive distinct behavior in microscopic nematode worms—and hold lessons for human brains
By Deserae E. del Campo
Special to UM News
Members of the Collins lab are, from back left, Assistant Professor Kevin Collins, Ph.D. students Bhavya Ravi and Pravat Dhakal, research associate Michael Scheetz, and undergraduate Layla Nassar.
CORAL GABLES, Fla. (January 4, 2017)—Kevin Collins carefully places a petri dish with what looks like a blotch of yellowish slime under a microscope. Magnified, the slime comes alive as hundreds of translucent worms, known as Caenorhabditis elegans, slither to and fro.
Growing to just one millimeter in length, these simple creatures have only 302 neurons, or nerve cells, in their bodies, a tiny fraction of the 80 billion or so neurons in the human brain. Yet, as Collins, a biologist at the University of Miami’s College of Arts and Sciences who studies the mechanics of neural circuits, notes, “Even the simplest animal with the simplest neural circuits have so much going on.’’
And these simple animals, Collins and fellow biologists from Yale University found in a recent study about nematode behavior, have a lot to tell us about our brains because, despite their simplicity, they share many commonalities with humans.
“Trying to figure out how 80 billion neurons in the human brain talk to each other and how that communication leads to changes in our behavior is very complicated,” Collins said. “But the nervous system in both nematode worms and humans is organized into small functional units called neural circuits, where neurons communicate with each other to control a simple outcome, such as behavior.”
For their study published in eLIFE, Collins and his collaborators focused on the nematode worm’s simplest neural circuit, the egg-laying behavior circuit, which is regulated by serotonin, a chemical neurotransmitter also found in humans and responsible for managing mood.
The researchers observed the worms’ behaviors through stages of maturity by recording the activity patterns of each cell in the circuit. They also manipulated the activity of cells and their ability to signal to each other to understand how the cells enable the worms to lay eggs. They found the circuit has “command neurons” that release serotonin to increase movement in the worms.
“Inside the worms, we believe serotonin is acting in a similar way in the human brain,” said Collins. “When the serotonin neuron is turned on, the worm is active and wants to do a specific behavior, such as locomotion or lays its eggs. In essence, we captured how the neuron in the worm gets turned on and off.”
As Collins noted, the signals that turn circuits on and off are general features of many neural circuits.
“It seems the serotonin helps respond to the rhythmic movement of the worm in different ways, similar to how serotonin is thought to drive arousal in the human brain,” said Collins. “For example, when a person is motivated or feels positive, that means neural circuits are communicating in a particular way. When that same person becomes depressed, it could be that those neural circuits are not communicating in the same way.”
Using what is called “calcium reporters,” researchers were able to see the neurons firing up inside the worm and record the changes in cellular activity during the egg-laying behavior. Researchers were also excited to learn that the same egg-laying circuit also mediates mating behavior.
“We now have an interesting question: What tells the female worm to lay its eggs or mate?” said Collins.
He hopes the study, “Activity of the C. elegans egg-laying behavior circuit is controlled by competing activation and feedback inhibition,” will lead to more insights on the mechanics of neural circuits.
His collaborators include Robert Fernandez, Jessica Tanis, Jacob Brewer, and Michael Koelle of Yale University’s Department of Molecular Biophysics and Biochemistry; Matthew Creamer of Yale University’s Interdepartmental Neuroscience Program; and Addys Bode of the University of Miami’s Department of Biology.
An international group of biologists discover how torrent ducks manage to thrive in low-oxygen environments.
By Jessica M. Castillo
A diving bird, the torrent duck is like a seal or penguin. Not in looks, of course, but in physiology. Like emperor penguins or Weddell seals, University of Miami researchers discovered, torrent ducks have among the highest concentrations of myoglobin, the protein that holds oxygen in muscle tissue.
That’s partly how this tiny waterbird species, averaging less than a pound, expertly dives in high-altitude rivers in the Peruvian Andes and has managed to survive for close to a million years in permanent states of hypoxia, or lack of oxygen. Travelers can see the ducks in the surging whitewater on the train ride to Machu Picchu.
“In most environments where you encounter hypoxia, it’s usually where animals will be able to escape it at some point,” said Neal Dawson, a postdoctoral biology researcher at the UM College of Arts and Sciences and McMaster University in Ontario, Canada, who with fellow UM biologists Kevin McCracken and Luis Alza discovered this adaptive trait on a July 2015 expedition. “In high altitudes, there’s no escaping it. These territorial ducks are stuck year-round with this hypoxia environment.”
The researchers’ expedition was part of a larger study, started in 2010, where scientists from UM, McMaster University, the University of British Columbia, the University of Alaska Fairbanks, and the CORBIDI institute in Peru set out to uncover what helps birds in the Andes thrive in such a high-altitude, low-oxygen environment.
For this latest study, the waterbird biologists focused on the torrent duck (Merganetta armata), a reluctant flier which, except when nesting, lives almost exclusively in the water. Working in remote villages north of Lima, the researchers learned how the ducks are able to hold their breath for a long time during repeated dives at high elevation by measuring their enzyme function across different metabolic pathways and the energy generation rates of their mitochondria, the cell’s powerhouse.
“As a diving species, the torrent duck will do everything it can to not fly,” noted Dawson, lead author of the study. “So, instead of looking at its ability to fly, we looked at its ability to dive. We looked at its leg muscles, enzymatic muscle activity, properties of the blood, and body measurements and noticed there are a whole host of changes that have really ameliorated its ability to dive at high altitudes.”
The bird has uniquely adapted to its resource-poor habitat. In addition to high levels of myoglobin, the researchers found that the torrent duck has high levels of hemoglobin, the oxygen-carrying protein in red blood cells. That enables it to “max out what their oxygen stores can be,” said McCracken, the James A. Kushlan Chair in Waterbird Biology and Conservation.
“If your hemoglobin levels were at 18 or 19 grams per deciliter, you’d be visiting your doctor to discuss it,” McCracken said. “The torrent ducks are going as high as 25. Double the concentration of yours. You would probably go into cardiac arrest if your hemoglobin was as high as a torrent duck’s.”
The scientists also discovered that the torrent duck’s hemoglobin has a high affinity for oxygen, which may affect its recovery time after a dive. The duck’s dive time is limited by the amount of oxygen it can hold in its lungs, air sacs, and intercellular oxygen stores.
“Once this oxygen runs out, the torrent duck has to resurface and recover quickly to be able to dive again,” said Dawson.
Recovery time is especially crucial for this species. “For the torrent duck, everything happens in the river,” said Alza, a doctoral student in the Department of Biology. Just as soon as they’re out of the water, the ducks are looking to dive back in for food or to escape external threats.
The oxygen-deprived torrent ducks also seem to be adapting to the high elevation by adjusting their energy consumption and fuel usage. Humans have access to energy from various fuel sources—including carbohydrates, fats and sugars. But most mammals in the wild are typically at the mercy of their environment and eat whatever energy sources are available; some even becoming specialists in digesting one source over another.
Digesting carbohydrates is more efficient per unit of oxygen, whereas digesting fats is more energy efficient per the actual amount of food that’s eaten.
The research team is currently analyzing the data but their preliminary results seem to contradict their initial hypothesis that this hypoxic species would tend to eat more carbs. The torrent ducks, it seems, tend to eat fats—mostly from aquatic insects—over carbs.
“Food might be more of a scarce resource than even oxygen at high altitudes,” said Dawson, who emphasized it’s still too early to say with certainty, but it looks like that’s what’s happening. “These ducks may be prioritizing getting their biggest bang for their buck every time they have a meal.”
The researchers also noted that, just over the last few years, they have seen a decline in the number of river ducks, which may be related to the impacts of the changing climate and increasing development near the duck’s habitat.
Poor development and infrastructure building pollutes the rivers with silt, choking aquatic insects and crashing the insect population. The ducks, with a staple diet of aquatic insects, must either move to another river or starve and die out.
Lima and other large cities along Peru’s Pacific coast depend on water from precipitation and glacial runoff. But the warming climate has melted many of the glaciers. In turn, rivers and artificial lagoons, built within the last 50 years for water retention, are drying up. Add in large and still growing urban populations and the pressures mount.
What does this mean for the ducks?
“No water, no ducks,” said Alza. “The duck is an easy way to monitor the river’s condition. If the ducks are still around, the river is quite healthy then.”
“The torrent ducks are a sentinel for conservation, particularly for protecting water resources used by local indigenous communities,” added McCracken, who also holds appointments as associate professor in the Department of Biology at the College of Arts and Sciences and in the Department of Marine Biology and Ecology at the Rosenstiel School for Marine and Atmospheric Science.
The researchers still have some more studies they’d like to conduct, such as on migration of juvenile ducks up and down the river, which would provide clues about the interplay between nature and nurture, or genetics and development in different environments. The scientists also would like to compare the torrent duck, a river duck with a vertical habitat, with the ruddy duck (Oxyura jamaicensis), another Andean diving bird species whose habitat is more isolated—in lakes and at either low or high altitude.
Their study “Mitochondrial physiology in the skeletal and cardiac muscles is altered in torrent ducks, Merganetta armata, from high altitudes in the Andes,” is published online in the Journal of Experimental Biology.
Catherine Newell, an assistant professor in the College of Arts and Science’s Department of Religious Studies, was recently awarded the David B. Larson Fellowship in Health and Spirituality at the John W. Kluge Center at the Library of Congress in Washington, D.C.
“Catherine’s fellowship is a testament to the relevance of interdisciplinary studies, and to the importance of her field of research for our students, our larger community, and our continued understanding of the complexity of our path to staying healthy or coping with illness,” said Maria Stampino, senior associate dean for academic affairs. “The college is proud that Catherine will represent us in our nation’s capital, in one of the foremost research centers.”
Starting in May 2017, Newell will have access to a rich collection of historical and current documents at the Library of Congress to research a project she has titled “Food Faiths: Health, Wellness, and the Science of Spiritual Eating.”
In her fellowship proposal, Newell’s explains how her research explores the way individuals “internalize scientific knowledge regarding health and diet, which they incorporate into their lives as a basis for personal spiritual practice.” Her research also explores the world of spiritual eating in which science is used to justify a diet and/or lifestyle by people who identify themselves not by a religion but by their diet—i.e., vegan, gluten-free.
“It’s an honor to receive this fellowship,” said Newell. “At the Library of Congress, I’ll have access to archival material, from historical letters to contemporary documentation, to help me conduct in-depth research for my book that I hope will contribute to the study of spirituality and health in modern times.”
During her seven month as a resident scholar at the Library of Congress, Newell will make a public presentation about her research and collaborate with other scholars conducting research at the library. The David B. Larson Fellowship endorses academic research on the relation of religion and spirituality to physical, mental, and social health.
Chantel Acevedo, far left, faculty advisor for Sinking City, launched the literary magazine with students and contributors last week.
CORAL GABLES, Fla. (December 2, 2016)—Miami’s vulnerability to climate change and sea-level rise goes far beyond infrastructure and institutions; it threatens the future of its most valuable asset—its diverse multicultural and multilingual community. Sinking City, a new online literary journal published semi-annually by students in the UM Master of Fine Arts program in creative writing, is committed to showcasing diverse, multilingual voices in works that drive conversations about the environment and other relevant topics.
“It’s very important for writers to also be good literary citizens, in other words, to give back to the community that they are a part of,” says Chantel Acevedo, A.B. ’97, M.F.A. ’99, associate professor of English and faculty advisor for Sinking City. “The work that putting together a literary journal takes can represent the best of that kind of citizenship.”
Sinking City hosted a launch party on Thursday at Tinta y Café in Coral Gables, where several contributors to the inaugural issue read their work, including UM poetry professor Maureen Seaton, who read her “Sonnet for Snapper Creek.”
Sinking City accepts poetry, fiction, nonfiction, and works of art.