Leptomeningeal collaterals regulate reperfusion in ischemic stroke and rescue the brain from futile recanalization.

Recanalization is the mainstay of ischemic stroke treatment. However, even with timely clot removal, many stroke patients recover poorly. Leptomeningeal collaterals (LMCs) are pial anastomotic vessels with yet-unknown functions.

The role of leptomeningeal collaterals in redistributing blood flow during stroke.

Leptomeningeal collaterals (LMCs) connect the main cerebral arteries and provide alternative pathways for blood flow during ischaemic stroke. This is beneficial for reducing infarct size and reperfusion success after treatment. However, a better understanding of how LMCs affect blood flow distribution is indispensable to improve therapeutic strategies.

Bidirectional astrocytic GLUT1 activation by elevated extracellular K.

The acute rise in interstitial K that accompanies neural activity couples the energy demand of neurons to the metabolism of astrocytes. The effects of elevated K on astrocytes include activation of aerobic glycolysis, inhibition of mitochondrial respiration and the release of lactate. Using a genetically encoded FRET glucose sensor and a novel protocol based on 3-O-methylglucose trans-acceleration and numerical simulation of glucose dynamics, we report that extracellular K is also a potent and reversible modulator of the astrocytic glucose transporter GLUT1.

Predicting Vessel Diameter Changes to Up-Regulate Biphasic Blood Flow During Activation in Realistic Microvascular Networks.

A dense network of blood vessels distributes blood to different regions of the brain. To meet the temporarily and spatially varying energy demand resulting from changes in neuronal activity, the vasculature is able to locally up-regulate the blood supply. However, to which extent diameter changes of different vessel types contribute to the up-regulation, as well as the spatial and temporal characteristics of their changes, are currently unknown.

Cost and speed of locomotion for rotifers.

The hypothesis that the ciliary locomotion of rotifers is size limited and that it accounts of a significant portion of the energy budget was investigated using the genera Brachionus and Asplanchna. Speed of movement was measured among clones of different size in Brachionus, which shows little size variation through development. The same tests were done among individuals of different size within a clone of Asplanchna, which shows significant postembryonic size increase.

Metabolic responses to temperature change in a tropical freshwater copepod (Mesocyclops brasilianus) and their adaptive significance.

Metabolic rates of Mesocyclops brasilianus from Lake Valencia, Venezuela, were determined at several temperatures spanning the environmental range (22-28° C). The QO's (oxygen consumption per unit weight) of all Mesocyclops stages from Lake Valencia are higher than most but not all QO's from temperate copepod species that have been studied. The QO is essentially static through naupliar development and shows a sudden jump between N6 and CI, which probably results from the major change in morphology and behavior at this point in the life history.