On Friday afternoon, Daniel Wesson, an assistant professor of neurosciences at Case Western Reserve University, presented his findings on the connections between sense of smell and the brain’s reward system.

Wesson, who earned his Ph.D. in biology from Boston University, delivered his lecture, “Identifying New Brain Mechanisms for Sensory Processing and Motivating Behaviors.” Wesson’s presentation focused on the olfactory tubercle, which is a small part of the brain that plays a role in multisensory integration, or the way that sensory information gets integrated into the nervous system.

He emphasized the role that the olfactory tubercle plays in the way that the brain rewards behaviors with regard to smell, meaning the way in which we derive pleasure from smell.

“Something that happens a lot in science is we start asking the questions that we are trained to think about … so as an olfactory person, what I was curious about was smell,” Wesson said.

The olfactory tubercle was first outlined by Albert von Kölliker, a Swiss physiologist and histologist, in 1896. Kölliker chose the name because of its close proximity to the olfactory bulb, a part of the brain heavily involved in processing smells. In the 1960s, it was discovered that the olfactory tubercle receives information about scents directly from the olfactory bulb.

Wesson’s research focuses on updating what he considers the incomplete model of the brain’s reward system. The olfactory tubercle is not present on the most widely used versions of the conditional system diagram. Wesson also focused on whether or not the olfactory tubercle impacts the way humans are motivated by smells, along with processing them.

“Motivation is not independent from processing,” Wesson said.

Wesson, working with his team of graduate students, used mice to conduct a number of experiments. He set up a source of water in the cage with the mice, which required a set number of licks from the mice to dispense the water, depending on which odor was present. The mice learned which odors corresponded with more water being dispensed.

“The licking shows the motivation,” Wesson said. “This is quite rapid transformation, the way these animals are encoding the same chemical stimuli based on brain association.”

Another experiment studied how the reciprocal sniffing behavior of two rats varied in three different positions: face to face, back to back and face to back, all of which represent different levels of dominance. The frequency of sniffing was measured and recorded and the results showed that reciprocal sniffing is dependent upon social status, as higher sniffing frequency was present in the dominant animal.

Wesson said that he believes this research shows that sniffing can be seen as a form of communication. Wesson said that he sees a future where the study of sensory processing can be used to gather further information on social conflict and communication. Additionally, he recognizes that his field of research has a long way to go, but highlighted the importance of starting small with smell instead of jumping to something like neurotransmitters, which are more frequently studied.

“You have to start from basics and work your way up,” Wesson said. “I’ve had my lab for about five and a half years now and because no one had looked at odor coding or tubercles, or no one had looked at these types of coding strategies … it would be kind of ignorant to just jump in and say, ‘Hey, how is it motivated by dopamine?’”

Kayla Murray, a junior majoring in psychology, said the lecture invited her to explore a topic she previously hadn’t considered.

“It was really interesting,” Murray said. “I hadn’t thought that much in depth about all of this. We kind of take for granted our sense of smell and never really think about all the processes and intricacies that go into it.”