Simultaneous two-voxel localized (1)H-observed (13)C-edited spectroscopy for in vivo MRS on rat brain at 9.4T: Application to the investigation of excitotoxic lesions.

(13)C spectroscopy combined with the injection of (13)C-labeled substrates is a powerful method for the study of brain metabolism in vivo. Since highly localized measurements are required in a heterogeneous organ such as the brain, it is of interest to augment the sensitivity of (13)C spectroscopy by proton acquisition. Furthermore, as focal cerebral lesions are often encountered in animal models of disorders in which the two brain hemispheres are compared, we wished to develop a bi-voxel localized sequence for the simultaneous bilateral investigation of rat brain metabolism, with no need for external additional references.

Attenuation of the blood flow response to physostigmine in the rat cortex deafferented from the basal forebrain.

Previous functional investigations in rats failed to demonstrate that the classical cholinesterase inhibitor, physostigmine, can compensate for cortical cholinergic deficit induced by deafferentation from the nucleus basalis magnocellularis (NBM). As these studies were carried out shortly after NBM lesion (1-2 weeks), we sought to determine whether compensatory effects of physostigmine would appear at a longer postlesion time (3-5 weeks). Cerebral blood flow was used as a quantitative measure of brain function.

The existence of biexponential signal decay in magnetic resonance diffusion-weighted imaging appears to be independent of compartmentalization.

It is generally believed that the apparent diffusion coefficient (ADC) changes measured by diffusion-weighted imaging (DWI) in brain pathologies are related to alterations in the water compartments. The aim of this study was to elucidate the role of compartmentalization in DWI via biexponential analysis of the signal decay due to diffusion. DWI experiments were performed on mouse brain over an extended range of b-values (up to 10,000 mm(-2) s) under intact, global ischemic, and cold-injury conditions.