Nanoscale organization is changed in native, surface AMPARs by mouse brain region and tauopathy.

Synaptic AMPA receptors (AMPARs) on neuronal plasma membranes are correlated with learning and memory. Using a unique labeling and super-resolution imaging, we have visualized the nanoscale synaptic and extra-synaptic organization of native AMPARs for the first time in mouse brain slices as a function of brain region and tauopathy. We find that the fraction of surface AMPARs organized in synaptic clusters is two-times smaller in the hippocampus compared to the motor and somatosensory cortex.

Automatic dendritic spine segmentation in widefield fluorescence images reveal synaptic nanostructures distribution with super-resolution imaging.

Dendritic spines are the main sites for synaptic communication in neurons, and alterations in their density, size, and shapes occur in many brain disorders. Current spine segmentation methods perform poorly in conditions with low signal-to-noise and resolution, particularly in the widefield images of thick (10 μm) brain slices. Here, we combined two open-source machine-learning models to achieve automatic 3D spine segmentation in widefield diffraction-limited fluorescence images of neurons in thick brain slices.

Structural Design of Multidentate Copolymers as Compact Quantum Dot Coatings for Live-Cell Single-Particle Imaging.

Quantum dots (QDs) are a class of semiconductor nanocrystal used broadly as fluorescent emitters for analytical studies in the life sciences. These nanomaterials are particularly valuable for single-particle imaging and tracking applications in cells and tissues. An ongoing technological goal is to reduce the hydrodynamic size of QDs to enhance access to sterically hindered biological targets.

Optimizing Quantum Dot Probe Size for Single-Receptor Imaging.

Quantum dots (QDs) are nanocrystals with bright fluorescence and long-term photostability, attributes particularly beneficial for single-molecule imaging and molecular counting in the life sciences. The size of a QD nanocrystal determines its physicochemical and photophysical properties, both of which dictate the success of imaging applications. Larger nanocrystals typically have better optical properties, with higher brightness, red-shifted emission, reduced blinking, and greater stability.

Multiple kinesins induce tension for smooth cargo transport.

How cargoes move within a crowded cell-over long distances and at speeds nearly the same as when moving on unimpeded pathway-has long been mysterious. Through an in vitro force-gliding assay, which involves measuring nanometer displacement and piconewtons of force, we show that multiple mammalian kinesin-1 (from 2 to 8) communicate in a team by inducing tension (up to 4 pN) on the cargo. Kinesins adopt two distinct states, with one-third slowing down the microtubule and two-thirds speeding it up.