Acute decrease in net glutamate uptake during energy deprivation

Acute decrease in net glutamate uptake during energy deprivation.

The extracellular glutamate concentration ([glu](o)) rises during cerebral ischemia, reaching levels capable of inducing delayed neuronal death. The mechanisms underlying this glutamate accumulation remain controversial. We used N-methyl-D-aspartate receptors on CA3 pyramidal neurons as a real-time, on-site, glutamate sensor to identify the source of glutamate release in an in vitro model of is...

Glutamate transport - relative rates of net uptake and heteroexchange

Neuronal activity and glutamate uptake decrease mitochondrial mobility in astrocytes and position mitochondria near glutamate transporters.

Within neurons, mitochondria are nonuniformly distributed and are retained at sites of high activity and metabolic demand. Glutamate transport and the concomitant activation of the Na(+)/K(+)-ATPase represent a substantial energetic demand on astrocytes. We hypothesized that mitochondrial mobility within astrocytic processes might be regulated by neuronal activity and glutamate transport. We im...

Acute decrease in renal microvascular PO2 during acute normovolemic hemodilution.

Large differences in the tolerance of organ systems to conditions of decreased O(2) delivery such as hemodilution exist. The kidney receives approximately 25% of the cardiac output and O(2) delivery is in excess of the oxygen demand under normal circumstances. In a rat model of acute normovolemic hemodilution (ANH), we studied the effect of reduced hematocrit on renal regional and microvascular...

Acute sleep deprivation reduces energy expenditure in healthy men.

BACKGROUND Epidemiologic evidence indicates that chronic sleep curtailment increases risk of developing obesity, but the mechanisms behind this relation are largely unknown. OBJECTIVE We examined the influence of a single night of total sleep deprivation on morning energy expenditures and food intakes in healthy humans. DESIGN According to a balanced crossover design, we examined 14 normal-...