Brain imaging technologies are crucial for understanding the relationships between specific areas of the brain and their function, helping to locate the areas of the brain that are affected by diseases or neurological disorders and build new strategies to treat them.
Our research activities
Functional Ultrasound imaging
Functional imaging that can see the brain in action is a tool of choice for biomedical research.
Since 2 years, our multidisciplinary team is developing an innovative imaging approach based on ultrasounds to record brain activity at unprecedented resolution (capable of accuracies within 100 microns that is the diameter of a hair) and in real-time. Our success is the result of combining high frequency (20 MHz) and high frame rate imaging (10.000 images par second) allowing us to follow hemodynamics in microvessels and in the entire depth of the brain which is not available to others imaging modalities.
The benefits of functional ultrasound (fUS) imaging include excellent safety record (ultrasounds are routinely used in hospitals), portability and affordable price compared with classic functional imaging modalities such as MRI or PET.
We have also demonstrated the efficiency of functional ultrasound imaging in the understanding of different diseases such as stroke, migraine, epilepsy in preclinical models.
On the strength of these results, we started a clinical trial entitled « ULtrasound imaging or surgical treatment of cortical dYSplasia » (acronym ULYS) including 20 patients who will benefit of this technology for treatment of epilepsy. By using brain ultrasound imaging, the neurosurgeon can track in real-time the efficient removal of pathological tissues and minimize the resection of healthy brain tissues to enhance outcome effectiveness.
Voltage Sensitive Dye imaging
Since almost a century electrical activities of hearth and brain have been visualized by electrocardiography (ECG) or electroencephalogry (EEG). Since three decades, these electrical activities of hearth and brain could also be visualized by fluorescent dyes. The general idea is to change the electrical signal of a cell into an optical signal. For that purpose fluorescent molecules are introduced in the plasma membrane of cells. These fluorescent dyes are lipophilic and localized in the lipidic bilayers of the plasma membrane of the cells. The fluorescent properties of the dyes will be modified with the changes of membrane voltage. These fluorescent dyes sensitive to potential are known under the name of “Voltage Sensitive Dyes” or VSDs. The goal of the present proposal is to develop new VSDs and to use them for visualization of hearth and brain electrical activities in several animal models including non-human primates. The final goal is to develop new non-toxic VSDs which could be use in humans. The first application would be done in the neurosurgery of epileptic foyer with the aim to precisely localize the pathological tissue.
What are the main challenges in neuroimaging we are working on?
- To offer a better spatiotemporal resolution at reduced cost;
- To combine neuro-imaging and behavior;
- To unify multimodal approaches (electrophysiology, optical, acoustic,...);
- To simplify end user interfaces;
- To develop specific analysis tools;
- To widespread novel technologies to the neuroscience community.
As long as our brain is a mystery, the universe, the reflection of the structure of the brain will also be a mystery.
Santiago Ramón y Cajal