Integrated multimodal cell atlas of Alzheimer's disease.

Alzheimer's disease (AD) is the leading cause of dementia in older adults. Although AD progression is characterized by stereotyped accumulation of proteinopathies, the affected cellular populations remain understudied. Here we use multiomics, spatial genomics and reference atlases from the BRAIN Initiative to study middle temporal gyrus cell types in 84 donors with varying AD pathologies.

Cell-type specific molecular signatures of aging revealed in a brain-wide transcriptomic cell-type atlas.

Biological aging can be defined as a gradual loss of homeostasis across various aspects of molecular and cellular function. Aging is a complex and dynamic process which influences distinct cell types in a myriad of ways. The cellular architecture of the mammalian brain is heterogeneous and diverse, making it challenging to identify precise areas and cell types of the brain that are more susceptible to aging than others.

Membrane Tension Modifies Redox Loading and Release in Single Liposome Electroanalysis.

Here, we present a study of how liposomes are loaded and release their contents during their electrochemical detection. We loaded 200 nm liposomes with a redox mediator, ferrocyanide, and used amperometry to detect their collision on a carbon-fiber microelectrode (CFE). We found that we could control the favorability of their electroporation process and the amount of ferrocyanide released by modifying the osmolarity of the buffer in which the liposomes were suspended.

Fast Detection of Single Liposomes Using a Combined Nanopore Microelectrode Sensor.

Here we report the development and characterization of a high throughput sensing device for single liposome detection. The device incorporates a quartz nanopipette positioned near a carbon-fiber microelectrode (CFE). Liposomes (∼200 nm diameter) loaded with Fe(CN) are driven out of the nanopipette orifice where they are sensed as a transient decrease in the measured ionic current (resistive-pulse analysis).

FIB-Milled Quartz Nanopores in a Sealed Nanopipette.

We report the use of laser-pulled quartz nanopipettes as a new platform for microfabricated nanopores. A quartz nanopipette is prepared on a laser puller and . A quartz nanopore can then be FIB-milled into the side walls of the sealed pipette and used to analyze single nanoparticles.

Electrodeposited Gold on Carbon-Fiber Microelectrodes for Enhancing Amperometric Detection of Dopamine Release from Pheochromocytoma Cells.

Exocytosis is an ultrafast cellular process which facilitates neuron-neuron communication in the brain. Microelectrode electrochemistry has been an essential tool for measuring fast exocytosis events with high temporal resolution and high sensitivity. Due to carbon fiber's irreproducible and inhomogeneous surface conditions, however, it is often desirable to develop simple and reproducible modification schemes to enhance a microelectrode's analytical performance for single-cell analysis.