"The sense of smell can give us basic insights into how the brain learns and organises information about the world around us," says Hanne Stensola.
She is a neuroscientist at the University of Agder (UiA).
Together with her partner and colleague Tor Stensola, she is currently busy with 34 small mice who are getting used to their new home. Each one will be given a name, fed, and cared for until they become accustomed to their surroundings at UiA's new neuroscience lab, which officially opens on 7 June 2024.
The mice will be going to mouse school
The mice don't just have to get used to their new environment, they should thrive and be fit. Eventually they will be going to 'mouse school', where they will learn various tasks to keep them mentally sharp and in good spirits.
"These mice are among our most important research partners. To find out how their brains work, we need healthy mice, which is why we take good care of them. At mouse school, they will become accustomed to us and to performing various tasks," Hanne says.
The goal is robust and relaxed mice. Eventually, they will have tiny electrodes attached to them and contribute to new knowledge about the brain.
Their first task will be to smell new things.
By studying the sense of smell, the Stensolas will provide us with fresh insights into how the brain learns and organises knowledge.
The sense of smell interprets reality
"We want to understand what the brain does with the sense of smell to categorise, identify, and interpret reality. We aim to understand the rules for how nerve cells in the brain cortex create identity and interpret reality," says Hanne.
"Among the senses, the sense of smell is the least dependent on the reality out there. You can't see or hear smell. Odors are molecules in the air. A banana and an orange don't smell the same to everyone. In other words, smell is largely interpreted and structured by the brain itself, regardless of what it actually smells like," Tor says.
In other words, smell is a subjective experience. The brain decides how to categorise and identify smells. And although smells are made up of different molecules and many different chemicals, the brain interprets them uniformly, as one thing.
The brain perceives persons and things
"The brain identifies what we experience. We don't experience the light on the retina. We also don't experience sound waves on the eardrum. We experience objects. And the person or thing retains its identity even if the sensory impression changes," Hanne says.
For example, you recognise your house no matter which side you view it from. Your mother may change her clothes and hairstyle, but you still identify her as your mother. How does your brain accomplish this?
Multiple networks of brain cells at work
"It is challenging to study how the brain creates identities, as identities are created by several networks of brain cells. These networks are large and spread across different areas of the brain," says Hanne.
The diversity and spread of networks make it challenging to study sensory impressions.
"We don't know how the brain uses the sensory streams from vision and hearing to create an identity or recognition. By studying the sense of smell, we can more easily investigate how the brain creates new identities. By exposing a mouse to a smell it has never come across before, we get an identity that is based solely on one sensory stream," Tor explains.
"What we are interested in with our new research is not understanding the sense of smell itself. Instead, we are interested in what the sense of smell can tell us about how the brain structures knowledge about the world," adds Hanne.
Reference:
Tor Stensola and Hanne Stensola: Understanding Categorical Learning in Neural Circuits Through the Primary Olfactory Cortex