Prof. Michel Simonneau (ENS Paris, France), 21st June 2017- Bw403


Prof. Michel Simonneau

From Centre Psychiatrie & Neurosciences, INSERM U894, Ecole Normale Supérieure Paris-Saclay, France


Brain diseases such as autism and Alzheimer's disease (each inicting >1% of the world population) involve a large network of genes displaying subtle changes in their expression. Abnormalities in intraneuronal transport have been linked to genetic risk factors found in patients, suggesting the relevance of measuring this key biological process. However, current techniques are not sensitive enough to detect minor abnormalities. Here we report a sensitive method to measure the changes in intraneuronal transport induced by brain-disease-related genetic risk factors using uorescent nanodiamonds (FNDs). We show that the high brightness, photostability and absence of cytotoxicity allow FNDs to be tracked inside the branches of dissociated neurons with a spatial resolution of 12 nm and a temporal resolution of 50 ms. As proof of principle, we applied the FND tracking assay on transgenic mouse lines that mimic the slight changes in protein concentration (~30%) found in the brains of patients. In both cases, we show that the FND assay is suciently sensitive to detect these changes. KTiPO4 (KTP) and SiC are materials known for their non-linear optical properties. Illuminated crystals - at the frequency f - can emit a light at the double frequency 2f. This property is called Second Harmonic Generation (SHG) and it is widely used in electro-optical.