Within the Department of Biological Sciences at Youngstown State University, there are many areas of research being explored by faculty and students alike. In a monthly series, we will highlight faculty research that covers various aspects of biomedical efforts from DNA to bacteria, fungi, and more.
Dr. Michael Butcher is an Associate Professor of Biological Sciences at YSU. He earned his PhD in Zoology from the University of Calgary. Afterward, he completed a two-year NSF post-doctoral fellowship at Clemson University before becoming a full-time professor at YSU.
At YSU, Dr. Butcher conducts three different types of research with assistance from multiple graduate and undergraduate students. The main focuses of his laboratory research are the mechanical properties and shape of limb bones, fiber architecture and force production in the limb muscles, and development of muscle fiber types. His most recent work involves studies of muscle form and contraction activity in tree sloths.
Every other year, Dr. Butcher has traveled to The Sloth Sanctuary in Limón, Costa Rica. This gives him the opportunity to study species of two-toed and three-toed sloths.
On his most recent trip, he and his research team visualized live muscle contractions of the sloths using implanted fine wire electrodes. They recorded muscle activity while sloths performed combinations of walking, climbing, and hanging exercises. In addition, Dr. Butcher and his team conducted very detailed dissections on cadaver sloths to learn about their muscle architecture.
“What we do is take geometric measurements of the muscles,” Butcher said. “For example, how long is the muscle belly, how long are the muscle fibers, at what angle are the muscle fibers? Then we apply a couple basic calculations.”
They could then estimate the force, power, and torque (strength) properties of sloth muscles. Dr. Butcher considers this approach to the study of muscle form and function “simple, but elegant.”
To understand his research interests, it is important to know some of the unusual characteristics of a sloth.
“Why a sloth?” Dr. Butcher was asked. “Because they’re old and interesting mammals that do something really different from what humans are capable of doing.”
In a sloth’s body, there is only about 24% muscle mass. Dr. Butcher and his students are finding that their muscles have a high tolerance for lactic acid and rarely fatigue, unlike skeletal muscles in humans. Much to his surprise, Dr. Butcher is also learning that sloths primarily use anaerobic mechanisms to allow them to conserve energy and resist fatigue. This contributes to a sloth’s ability to hang from tree limbs for extended periods of time.
Other factors that relate to the strength and stamina of sloths are lower body temperature, lower metabolism, and slower digestion than most placental mammals.
“Sloths also have a network of blood vessels in their forearms that lowers the temperature of the muscles,” Butcher said. “This allows the muscles to remain strongly contracted for gripping branches while using energy at a slower rate.”
With these distinctive characteristics, sloths can conserve a tremendous amount of energy. For this very reason, Dr. Butcher finds sloth research remarkably insightful.
Dr. Butcher does not simply perform research to learn more about muscle structure-function in sloths, but rather to give further evidence of the performance range of muscles, in general. He wants to continue studying how muscles are put together and how they work, as functionality is diverse for animals depending on their lifestyle.
While this research has medical applications such as bioengineering artificial muscles and limbs, Dr. Butcher remains committed to fundamental science where his findings contribute towards education in the scientific community, future textbooks, and enhancement of the courses that he teaches at YSU.
Dr. Butcher stresses the immense contribution from his students. He believes that they are vital to his research efforts. To further his studies in primitive mammals Dr. Butcher plans to travel to Argentina this fall to investigate muscle properties in rare species of armadillos.