ComBATing Hearing Loss

Dr. Christine Portfors in the bat lab

By Jacob Schmidt

An associate professor of biology and neuroscience at Washington State University Vancouver, Portfors also heads up the Hearing and Communication Lab. More commonly known as the “Bat Lab,” the lab centers around Portfors’ use of bats and mice in an attempt to uncover how complex sounds are processed by the human auditory system and to determine how age-related hearing loss impacts this processing.

Furry friends

Non-threatening bat faceAny notions of a chilly bat cave are quickly dispelled when entering Portfors’ office. Her space exudes warmth and open-door friendliness. Pictures and sketches of bats line her walls and a bright, stained-glass pane of a bat in flight hangs in her window. While Portfors has openly embraced the bat community, many in the WSU Vancouver campus community do not immediately understand the harmless and environmentally beneficial nature of bats.

“My bats are not vampire bats,” laughed Portfors. “We use fruit bats that are kept in a flight room and cannot escape. Aside from that, they are just really cool, and their native counterparts are good for controlling the
mosquito population.” Although Portfors’ degrees in physiology, biology and human biodynamics have prepared her for her research, her extensive knowledge and affable nature towards the furry creatures stems entirely from a study-abroad program she participated in as a graduate student.

“I was sitting in the middle of some savannah in Zimbabwe in the dark of the night watching these animals fly around the African sky. All I could think was, ‘They can’t see, but they’re using sound. I can’t hear it, and I don’t understand how their brain is doing it, but this is totally cool—this is what I want to study.’ It was a fabulous experience,” recalled Portfors.

The experience spurred Portfors toward a future of bat studies and hearing research. She has studied multiple bat species, although her lab now consists entirely of carollia perspicillata—more commonly known as the short-tailed fruit bat. Indigenous to South and Central America, Portfors’ fruit bats communicate through emitting high-pitched frequencies indiscernible to the human ear.

Famous for echolocation, bats use the sounds and returning echoes to create a detailed image of their surroundings. Since the bats rely primarily on this sense, a larger portion of the brain is devoted to auditory processing. For Portfors, the bat auditory processingsystem functions as a pivotal piece of her research ambitions.

Finding answers

From a scientific perspective, piecing together how the human brain works is not an easy task. Studying the brain and processing systems of bats enables researchers to come closer to unraveling the mysteries of the human mind.

“It’s all about how the brain works. In particular, how the brain works to understand sounds,” said Portfors about her research. “We, as humans, use sound for a lot of things, and one of the biggest things we use it for is to communicate. People who have normal speech development have no problem doing it because we hear all these sounds and we learn to distinguish what each sound means as we grow up.”

Portfors’ research focuses on those who do not have normal speech development, particularly those who suffer from communication disorders and hearing loss. Hair cell receptors in the ear allow us to process sound, but when we are exposed to loud noise, it may damage the receptors and result in hearing loss.

Despite significant research on the topic, hearing loss remains a widespread health concern facing many Americans. According to a study by the National Institute on Deafness and Communication Disorders, nearly one in five Americans suffer from some form of hearing loss—the ramifications of which extend into our social well-being as well as physical health.

“Because humans are social, we use speech a lot in social interactions. As you lose the ability to hear sounds and discriminate, you risk facing severe social isolation. Individuals who face deafness on a daily basis are far more likely to attempt suicide than those with other sensory deprivations such as blindness,” said Portfors.

Portfors aims to combat the social issues associated with hearing loss—mainly through using her research to improve cochlear implant technology. Unlike hearing aids, which simply amplify sounds, cochlear implants rely on generated electrical impulses.

“Cochlear implants encode the sounds coming into the ear and convert them to electrical current to stimulate the corresponding part of the cochlea. It’s a fundamental technology, but it’s not perfect—there is room to make this better,” said Portfors.

Thanks in part to a lab loaded with sophisticated technology, Portfors is on her way to making this happen. High-powered microscopes allow her to see brain cells and high-end electronics enable her to pick up the current change of firing neurons. These current changes are key because they reveal when the brain is responding to a particular type of sound.

Equally important is software that allows Portfors to visualize ultrasonic sounds. Since both bats and mice emit high-pitched sounds that the human ear cannot hear, Portfors uses specialized ultrasonic microphones to record the sounds then relies on the software to map out the features of the sound. Through this, further illumination is cast on how the brain processes certain sounds.

Grants and recognition

Portfors’ work has not gone unnoticed. Since starting at WSU Vancouver in 2001, she has tallied up nearly $2 million in federal grants. The majority of these grants have come from the National Institutes of Health and the National Science Foundation. She has also received grants from the Howard Hughes Medical Institute, the Bureau of Land Management and Bat Conservation International.

The NSF garnered Portfors further recognition by highlighting her research concerning mice mating vocalizations in a 2011 video for the online science magazine, Science Nation.

Rounding out her portfolio, Portfors has also given more than 40 presentations at national and international scientific conferences including the International Bioacoustics Congress in La Rochelle, France and the Society for Neuroscience Annual Meeting in Washington, D.C.

In addition to her international recognition, Portfors was recognized in May 2012 with WSU Vancouver’s highest research honor—the Chancellor’s Award for Research Excellence.

“It’s nice to be recognized and honored,” said Portfors reflecting on receiving the award. “I think it is an important award to give to a faculty member every year because it reinforces the tenet that WSU Vancouver is a Tier I research institution and many of us are internationally known in our research field.”

Building a future

Bat hanging in bat lab environmentWhile Portfors’ funding and research recognition could propel her past the day-to-day duties of teaching and advising, Portfors focuses on using her academic success to help build a future in areas previously untapped on campus. Portfors observed a growing need for more pre-health degree options and worked in conjunction with the psychology department to bring a bachelor’s of science in neuroscience to the WSU Vancouver campus. “This degree will bring an opportunity for students interested in a pre-health career to get a degree where that is the focus. They are going to take courses that are totally related to pre-health, and they will have opportunities to work with researchers who study the brain,” said Portfors. “It will also produce graduates who can help with the health personnel crisis that’s going to be happening in this area within the next 10 years.”

Along with the benefits the degree will provide to students and the local community, Portfors thinks it will add greater value to the university and its offerings.

“Undergraduate neuroscience degrees are among the fastest growing degrees in the country. As the degree becomes more established and well known, it is going to attract more and more students specifically to come to this
campus,” said Portfors.

Students pursuing the neuroscience degree will have the chance to work directly with Portfors studying the brain processes of the bats and mice in the lab. This student-centered approach is nothing new for Portfors. She currently works with four graduate students in her lab and regularly brings in undergraduate students to participate in the basics of her research.

“For students to be involved in research, they really need to be doing it for the right reasons—they need to have an intrinsic interest in the work—not just be going through the motions for a letter of recommendation for graduate school,” said Portfors.

Not every person’s interests will lead them to a relationship with bats, but Portfors believes in the importance of intrinsic motivation and hopes students will take flight and find the same passion in research that her work has given her.

This article appears in the Fall 2012 issue of NW Crimson & Gray Magazine

NW Crimson & Gray magazine is a quarterly magazine produced by Washington State University Vancouver that highlights the WSU Vancouver community and higher education in SW Washington. Subscribe for free or download the issue online.