WHEN THE PAST MEETS INNOVATION: NEW GENERATION MICROSCOPY TECHNIQUES TO EXPLORE ANCIENT BRAINS
Two innovative histology techniques will be used to precisely explore the brain tissues from the Geneva brain collection: expansion microscopy and tissue clearing. These methods push the boundaries of traditional histological techniques, especially for ancient samples dating back to the 20th century.
- Expansion microscopy is based on an amazingly simple yet powerful idea: "stretching" the tissues to observe them more clearly. This method involves soaking the samples in a special gel that swells by absorbing water. During this process, the internal structure of the tissues remains intact, but their size increases—up to 10 times. This allows for the visualization and marking of microscopic details that are difficult to discern with conventional techniques, such as neuronal synapses, which are often affected in neuropsychiatric disorders.
- Tissue clearing, or "tissue clearing," takes a complementary approach. Rather than enlarging the tissues, this technique aims to make them transparent. They can then be explored in depth using three-dimensional microscopy techniques. This enables the observation of large brain regions at the microscopic scale, allowing for the study of changes occurring in neuronal circuits during brain diseases. This method also makes it possible to link anomalies at the microscopic level with larger-scale changes observed with medical imaging techniques such as MRI.
By combining these two approaches, we will be able to explore ancient brain samples with unprecedented detail on a large scale. These tools will allow us to revisit historical medical collections to reveal new information about the physiological structure of the organ and previously unknown pathological mechanisms.
Further readings :
Tissue clearing of a tissue sample (left) to be visualized on a light sheet microscope (middle) for a precise 3D study of the tissue (right).
21 Jan 2025
