Gabrielle Britton, assistant professor of psychology at Lafayette, has received a grant from the National Institutes of Health to study how the brains of animals react to both threats and “safety signals,” which may provide insight into some anxiety-based human disorders.
NIH is one of the world’s foremost medical research centers, and the federal focal point for medical research in the United States. The grant will cover equipment costs for Britton, who is involving several Lafayette students in her research, including current EXCEL Scholar Jennifer Katzenstein of Chittenango, N.Y.; upcoming summer EXCEL Scholar Josh Brodsky of Needham, Mass.; and Jessica Papada of Hazleton, Pa., who is taking an independent study this term with Britton. All three students are neuroscience majors in the Class of 2003.
In Lafayette’s EXCEL Scholars program, students collaborate closely with faculty on research projects while earning a stipend.
“I’m planning on doing all of the work with students,” says Britton. “They are integrated into everything. They’re involved in the design of the studies and the methodology. I do brain surgery and run subjects through learning paradigms, so the students conduct neuroscience research, analyzing research and data.”
The role of brain systems in learning and memory has been studied extensively using a variety of learning systems in conjunction with neurobiological techniques, notes Britton. One approach that has provided insight into the role of brain systems in simple forms of motor learning is classical “eye-blink conditioning,” in which a neutral stimulus (such as a tone) is repeatedly paired with a stimulus (such as a mild air puff to the eye) that causes a reflexive blinking response. After several training trials, the animals learn to blink in response to the tone alone in anticipation of the air puff.
“This simple form of learning is mediated entirely by a neural circuit in the brain stem and cerebellum, although other brain systems (outside the circuit) are engaged under special circumstances,” says Britton. “For example, there is evidence to suggest that the amygdalar system, which has been implicated in learning about fear-inducing stimuli, may become involved in eye-blink conditioning when the animal is learning about the emotional properties of the air puff stimulus. However, the relationship between amygdalar activity and eye-blink conditioning has not been characterized enough to allow for a detailed understanding of how the amygdalar system interacts with the cerebellar-brain stem system during eye-blink conditioning.”
Britton seeks to determine the role of amygdalar neurons in eye-blink conditioning by using behavioral procedures used in studies of fear conditioning. The aim is to measure autonomic responses such as heart rate during eye-blink conditioning to characterize the contribution of emotional responses to the learning of the eye-blink response. The results will provide a basis for conducting neural recording studies that may reveal how brain systems interact during simple forms of learning, she says.
“Moreover, these studies may provide a neurobiological explanation of how previously neutral stimuli can acquire the ability to produce emotional responses,” adds Britton. “Such an explanation is relevant in light of evidence obtained in clinical studies of emotional disorders, which suggests that emotionally arousing stimuli play a role in various forms of anxiety disorders.”
Katzenstein is studying how lesions on the amygdala, the part of the rat’s brain related to fear-conditioning and emotion, affect the rats’ ability to respond to eye-blink conditioning.
“By lesioning different nuclei, rendering them useless, we can determine if the rat acquires the task, and if not, then a brain area can be correlated,” she says. “The most important thing about this project is that I am a member of a research team that must work together to learn about a function of the amygdala that has not been as widely studied as some others. We are looking at a brain system that may help us understand how fear is involved with the amygdala. This is very exciting.”
Katzenstein considers Britton “a fantastic addition to the neuroscience program” and says the professor’s experiences with electrophysiology will add a new dimension to the department “that can help to round out this new and fast-growing major.”
President and founder of Lafayette Society for Neuroscience, Katzenstein believes her EXCEL experience will help her decide whether to pursue to graduate school in neuroscience, medical school, or physician’s-assistant school.
Britton joined the Lafayette faculty last fall and already has introduced new opportunities in classes. In last semester’s Physiological Psychology course, which examines the neural, hormonal, and physiological bases of animal and human behavior, students injected female and male hormones into rats and studied the behavioral effects. On a different group of rats, they conducted surgery to create lesions in different parts of the anesthetized rats’ brains, then sutured them up afterwards; all of the animals survived. They followed up with learning experiments to determine the effects of the lesions.
“Students get to see how very small areas of the brain are controlling different aspects of learning,” says Ann McGillicuddy-DeLisi, Marshall R. Metzgar Professor and head of psychology. “It’s just worked beautifully. In the last lab of the semester, students [did] brain slides to see how the brain has changed.”
Britton, whose research interests include neurobiology of learning and memory, also is designing a new course on neurophysiology, which takes an in-depth look at brain cells.
“As far as we know, there are no liberal arts colleges and only a few universities that offer a course on this,” says McGillicuddy-DeLisi.
The department will purchase equipment for the course to allow students to conduct intercellular recordings of animals. The instruments will monitor the neural signals sent through cells – expressed in electrical activity — while another part of the subject’s brain is being stimulated.
Britton received her bachelor’s degree in psychology in 1991 from Vanderbilt University and a master’s in psychology from Mount Holyoke College in 1994. She completed a Ph.D. in Animal Learning and Neuroscience in 2000 at Indiana University, where her research focused on the cellular basis of learning and memory at molecular and systems levels.
Primarily interested in the neural basis of classical inhibitory conditioning (i.e., learning about the absence of environmental events), Britton has explored this question using electrophysiological recording techniques in both invertebrate and vertebrate systems. As a National Institute of Mental Health post-doctoral fellow at Indiana, she explored the role of the amygdala fear system in associative motor learning in rats.
Britton regularly presents her research at the annual Society for Neuroscience Meetings, and has co-authored research articles in Journal of Neuroscience, Brain Research, Neurobiology of Learning and Memory, and Journal of Comparative Psychology. She received the Indiana University Teaching Excellence Award, as well as numerous pre-doctoral research awards. She is a member of the Society for Neuroscience and Sigma Xi Research Society.
With the goal of gaining insight into human anxiety disorders, Joshua Brodsky ’04, a neuroscience major, studied how rats react to threats and periods of safety in EXCEL Scholars research with Gabrielle Britton, assistant professor of psychology.