On the third floor of the Taylor Science Center, behind several series of locked doors, lives a thriving colony of rodents. It is rats, especially, and their behavior, that prompted Assistant Professor of Psychology Siobhan Robinson to enlist six Hamilton students to assist her with research this summer.
Neuroscience concentrators Sara Aldrich ’19, Tatenda Chakoma ’18, Abigail Dayton ’19, Fiona McLaughlin ’19 and Allison Mogul ’18, and psychology concentrator Gianna Davino ’20 all worked under Robinson, studying the behavior of rats under a variety of conditions.
The ultimate aim of this research is to better understand behavioral and cognitive deficits by examining the neuroanatomy and neurochemistry behind learning, memory and motivation.
Mogul and Davino helped Robinson investigate context learning (learning through the actual, practical experience with a subject) in rats with respect to higher order fear conditioning (a form of learning in which a stimulus is first made meaningful or consequential for an organism through an initial step of learning, and then that stimulus is used as a basis for learning about some new stimulus.)
The team examined the role of the retrosplenial cortex (RSC), the part of the brain important for memory of context, in learning and remembering entire contexts (filled with multiple sensory cues), versus individual cues.
In the end, Robinson found that both the control and the RSC-lesioned rat can differentiate between contexts in first order fear conditioning. But in higher order conditioning, the lesioned rats are unable to discriminate between contexts. This conclusion is one Mogul will further investigate in her thesis with Professor Robinson as her advisor.
In the spirit of continuing research, Aldrich is furthering the work of Olivia Surgent ’17, a neuroscience student who attempted to create a new animal model of autism. Surgent injected six young rats with a drug called bicuculline (bic rats) and then compared their sensory-based learning and decision-making deficits with those of her control rats.
Through this research, Surgent identified some unusually repetitive behaviors in bic rats, such as poking their nose into a food cup thousands of times per hour. The repetitive behavior is a characteristic sign of autism spectrum disorder in humans.
Surgent, however, in her research, was unable to characterize the social deficits (an inability or an unwillingness to act in accordance to age, physical condition and intelligence) of this possible model of autism, which is where Aldrich came in. By performing a series of experiments with scented wooden beads, Aldrich and Professor Robinson have constructed data that is either significant or trending toward significance on their bic rat hypothesis, an exciting result. Aldrich will present a poster with her and Surgent’s data at the Family Weekend poster session and at the NY6 undergraduate conference at Skidmore in September.
Chakoma is also working with receptors. He is learning a chemogenetic (the process by which macromolecules can be engineered to interact with previously unrecognized small molecules) technique that involves surgically infusing DREADDS (Designer Receptors Exclusively Activated by Designer Drugs) in rat brains.
These designer receptors are activated only when the rat is injected with a particular drug, allowing the team to spatially and temporally control brain activity without physically destroying any neurons. The brain images collected from Chakoma’s procedures will be sent to the NASA and NSF grants on which Robinson is collaborating.