3D visualization of smell can help diagnose diseases

The study of networks within the nervous system for a long time was limited to the existing equipment. Ultra-fast method of 3D rendering called SCAPE microscopy, allows us to delicately deal with a large amount of fabric without damaging the fine network of living cells.

“This technology will provide new understanding of how the brain decodes the information to reproduce the feelings, thoughts and actions,” said Edmund Talley, Director of the National Institute of neurological disorders and stroke. Microscope SCAPE is incredibly useful for studies where large areas of tissue are to be observed in real time. With this technology, cells are not damaged and can be rendered at high speeds in three dimensions. So scientists can explore a lot of new questions that could not be explored before.

For example, the olfactory epithelium is located deep inside the nose and consists of many thousands of nerve cells, each of which contains one specific receptor that reacts to a certain smell. Studies using individual, simple odors show that when we sniff, a certain combination of nerve cells is activated, forming a code that is interpreted by the brain as a specific smell. In the past, scientists could study only a limited portion of this region, and the methods they used, could damage the tissue, hindering definitive conclusions.

The olfactory epithelium appeared to be an ideal target for study using the SCAPE as the nerve cells responsible for detecting odors are randomly distributed. This means that it is important to observe as many cells to draw conclusions about the nature of their activity.

Using SCAPE, the researchers were able to measure thousands of olfactory nerve cells at the same time. The experts used the smells like: almond, floral/Jasmine and citrus. Although the results of observation with such simple patterns have already been predicted by existing theory, when the researchers exposed the tissue to smell for two or three odor mixed together, they saw a much more complicated system of interacting reactions of nerve cells than expected.

“We thought that the response to the mixture of smells will be very similar to the sum of the responses to the original scents,” said Stuart Fierstein, senior author of the study. “Instead, we observed a complex interaction, in which the second odor was strengthened by the reaction of a neuron in the first or, in other cases, suppressed it.”

Given that almost all the smells around us are complex mixtures, this mechanism can explain how we distinguish a huge variety of flavors, and why it is often difficult to separate the individual ingredients of the mixture.

Data from this study can also help in detecting early symptoms of diseases. For example, such as Alzheimer’s and Parkinson’s. These diagnoses often have the probability of loss of smell as an early symptom.