Dr Leonardo Belluscio is a brain scientist with a particular interest in smell. The loss of smell can be an early symptom of neurodegenerative diseases like alzheimers and it's hoped that better understanding how smell operates in the brain could provide clues to how and why those illnesses happen.
Most recently, Dr Belluscio’s team at the National Institute of Health in the United States has uncovered how stem cells in the brain are critical to re-establishing networks of neurons responsible for smell in mice. Dr Belluscio’s in new Zealand at the invitation of Auckland University’s Centre for Brain Research.
Read an edited excerpt of the interview below:
How does the brain process smell?
That’s a very complicated question and the short answer is, we don’t quite know. Although we know a lot about how the brain is organised and how it basically takes a lot of information coming in the nasal cavity, which is really the first place that odours are detected and at an anatomical level, how that information is then sent into the brain through passages that go through a plate that then essentially passes that information from the outside world directly to the brain. How that information is then interpreted is a much more complicated question and there is a lot of groups that are trying to understand that, including ourselves.
You’ve been carrying out experiments with mice, what are the results telling us?
Much of my work is tackling that question, which is, how the brain really makes sense of smells that we detect in the outside world and one of the first places that that information is received at a place called the olfactory bulb, which sits in the base part of the brain in humans. So a lot of our focus is trying to make sense of how the signals from the sensory epithelium that lines the nasal cavities make sense of the information that comes in, what patterns that may have… can it tell it something about how a certain smell can produce a certain pattern of activity? Then also what happens over time as we become familiar with the smell, do the patterns change? Things of that sort. A lot of our work has really focused on this structure - the olfactory bulb - which is quite a remarkable structure actually. There is regeneration that occurs continuously in an organism, at least in mice. In humans it is still a hotly debated topic. What we had found was the regeneration that goes on in the olfactory bulb is actually critical to maintaining the stability of the circuits that are present in the olfactory bulb.
So this is the link with neurodegenerative diseases that you are exploring?
The neurodegeneration has emerged as a parallel project because we were aware of the fact that neurological dysfunctions and smell have a history. The loss of a sense of smell is one of the earliest things that people report when they are diagnosed with some of these disorders. So what we wanted to understand was, can we get some kind of meaningful idea for why the sense of smell is one of the things that goes first. Is there something special about the olfactory system that could indeed render it susceptible as an early indicator for some of these disorders? That’s really some of our focus with neurodegeneration emerged from.
