Diffusion of D-glucose measured in the cytosol of a single astrocyte.

Astrocytes interact with neurons and endothelial cells and may mediate exchange of metabolites between capillaries and nerve terminals. In the present study, we investigated intracellular glucose diffusion in purified astrocytes after local glucose uptake. We used a fluorescence resonance energy transfer (FRET)-based nano sensor to monitor the time dependence of the intracellular glucose concentration at specific positions within the cell.

Dynamic monitoring of cytosolic glucose in single astrocytes.

It is becoming increasingly clear that astrocytes are no longer playing a subservient role to neurons in the central nervous system (CNS), and that these cells are being considered as active communication integrators. They respond to neurotransmitters by the regulated release of gliotransmitters. The delay between neurotransmitter activation and the release of gliotransmitters from astrocytes is in the time-domain of subseconds, much slower than the submillisecond synaptic delay.

Changes in cytosolic glucose level in ATP stimulated live astrocytes.

Astrocytes which lie between brain capillaries and neuronal terminals are the primary site of glucose uptake and have a key role in coupling synaptic activity to glucose utilization in the central nervous system (CNS). We used a fluorescence resonance energy transfer (FRET) based approach to monitor cytosolic glucose in astrocytes. We determined the effect of increasing extracellular glucose concentrations on FRET ratio as a measure of increased cytosolic glucose in astrocytes.

Astrocytes and energy metabolism.

Astrocytes are glial cells, which play a significant role in a number of processes, including the brain energy metabolism. Their anatomical position between blood vessels and neurons make them an interface for effective glucose uptake from blood. After entering astrocytes, glucose can be involved in different metabolic pathways, e.

Analysis of confocal images using variable-width line profiles.

A line profile of fluorescent intensities in confocal images is frequently examined. We have developed the computer software tool to analyse the profiles of intensities of fluorescent probes in confocal images. The software averages neighbouring pixels, adjacent to the central line, without reducing the spatial resolution of the image.

Rosiglitazone modulates insulin-induced plasma membrane area changes in single 3T3-L1 adipocytes.

In this study we hypothesized that rosiglitazone, an antidiabetic high-affinity agonist for the peroxisome proliferator-activated receptor gamma, affects the plasma membrane (PM) turnover in single 3T3-L1 adipocytes. To study the PM turnover, the patch-clamp electrophysiological method was used to measure changes in membrane capacitance (Cm), a parameter linearly related to the PM area. Microscopy results show that the presence of rosiglitazone in the differentiating medium significantly increased the differentiation of 3T3-L1 adipocytes in cell culture, based on oil red O-stained area (11.