Gadolinium diethylenetriamine penta-acetic

acid (Gd-DTPA) was injected to visualize and characterize the permeability of the BBB at different time points after disruption. The concentration of Gd-DTPA in the brain parenchyma was determined as a function of time after injection.

RESULTS: A typical pattern of signal change as a function of time was observed this website in the treated hemisphere of all animals. Initially, a slight signal decrease was observed in T1-weighted images followed by a strong increase corresponding to the injection of Gd-DTPA. Two different mechanisms seemed responsible for the distribution of Gd-DTPA within the parenchyma: 1) a direct diffuse increase in capillary permeability, and

2) a diffusion process in the interstitial compartment. Initial results showed that Tideglusib concentration the barrier opens immediately after the procedure and for at least 30 minutes.

CONCLUSION: The methodology described in this article allows monitoring of the dynamics of the BBB disruption process and characterization of its physiology in vivo, and represents a marked advantage over postmortem static studies.”
“We formulated responses in functional traits by competitive communities to continual environmental changes, and examined the association of the trait dynamics with species richness and interspecific competition. As an aggregate measure for community properties we employed the mean community trait value as the species traits averaged over an entire community with weighting by relative species abundances. For three particular types of community, to in which there was competition for abiotic resources, competition for biotic resources, or species packing on an environmental gradient, we analytically proved that the responses of the mean community trait to environmental change were determined by the total trait range in the community but were weakly associated with the strength of competition and the number of species. These results were provided with simplifying assumptions that

the species trait determining the resource utility equally spaced along an univariate resource axis and the competition between species was symmetrical between pairs of competing species and within the entire community. Some numerical simulations based on stochastically-generated communities and randomly-sampled natural communities indicated that relaxation of the simplifying assumptions did not considerably violate the above conclusion. The suggested determinacy of trait dynamics with variable species richness and competition regime implies that aggregated description of communities in terms of trait distributions among composite species is relevant in predicting community responses, in terms of functional traits and ecosystem function, to environmental changes. (C) 2008 Elsevier Ltd. All rights reserved.