One-dimensional deterministic transport in neurons measured by dispersion-relation phase spectroscopy

One-dimensional deterministic transport in neurons measured by dispersion-relation phase spectroscopy.

We studied the active transport of intracellular components along neuron processes using a new method developed in our laboratory: dispersion-relation phase spectroscopy. This method is able to quantitatively map spatially the heterogeneous dynamics of the concentration field of the cargos at submicron resolution without the need for tracking individual components. The results in terms of densi...

Dispersion-relation phase spectroscopy of intracellular transport

We used quantitative phase imaging to measure the dispersion relation, i.e. decay rate vs. spatial mode, associated with mass transport in live cells. This approach applies equally well to both discrete and continuous mass distributions without the need for particle tracking. From the quadratic experimental curve specific to diffusion, we extracted the diffusion coefficient as the only fitting ...

Three-dimensional intracellular transport in neuron bodies and neurites investigated by label-free dispersion-relation phase spectroscopy.

Due to the limitations of fluorescence imaging techniques, the study of intracellular cargo is typically restricted to two-dimensional analyses. To overcome low light levels and the risk of phototoxicity, we employ quantitative phase imaging, a family of full-field imaging techniques that measure the optical path length shift introduced by the specimen. Specifically, we use spatial light interf...

Determination of two-dimensional phonon dispersion relation of graphite by Raman spectroscopy

Spatially resolved ballistic optoelectronic transport measured by quantized photocurrent spectroscopy.

GaAs-based quantum point contacts (QPCs) are exploited to spatially resolve and analyze the ballistic, nonequilibrium flow of photogenerated electrons in a nanoscale circuit. Electron-hole pairs are photogenerated in a two-dimensional electron gas (2DEG), and the resulting current through an adjacent QPC is measured as a function of the laser spot position. The transmission of photogenerated el...