Cerebral blood flow at one year after controlled cortical impact in rats: assessment by magnetic resonance imaging.

Progressive tissue loss and delayed cognitive deficits are seen in rats during the initial year after experimental traumatic brain injury (TBI). As much as 10% of parenchymal volume is lost even in the contralateral hemisphere by 1 year after controlled cortical impact (CCI) in rats. Progressive declines in cerebral blood flow (CBF) are also associated with advanced age and neurodegenerative diseases.

Regulation of interstitial excitatory amino acid concentrations after cortical contusion injury.

Increases in brain interstitial excitatory amino acid (EAA(I)) concentrations after ischemia are ameliorated by use-dependent Na+ channel antagonists and by supplementing interstitial glucose, but the regulation of EAA(I) after traumatic brain injury (TBI) is unknown. We studied the regulation of EAA(I) after TBI using the controlled cortical impact model in rats. To monitor changes in EAA(I), microdialysis probes were placed in the cortex adjacent to the contusion and in the ipsilateral hippocampus.

Regulation of interstitial excitatory amino acid concentrations after cortical contusion injury.

Increases in brain interstitial excitatory amino acid (EAA(I)) concentrations after ischemia are ameliorated by use-dependent Na+ channel antagonists and by supplementing interstitial glucose, but the regulation of EAA(I) after traumatic brain injury (TBI) is unknown. We studied the regulation of EAA(I) after TBI using the controlled cortical impact model in rats. To monitor changes in EAA(I), microdialysis probes were placed in the cortex adjacent to the contusion and in the ipsilateral hippocampus.

Cerebral perfusion during anesthesia with fentanyl, isoflurane, or pentobarbital in normal rats studied by arterial spin-labeled MRI.

The influence of anesthetic agents on cerebral blood flow (CBF) was tested in normal rats. CBF is quantified with arterial spin-labeled MRI in rats anesthetized with either an opiate (fentanyl), a potent inhalation anesthetic agent (isoflurane), or a barbiturate (pentobarbital) using doses commonly employed in experimental paradigms. CBF values were found to be about 2.

Early perfusion after controlled cortical impact in rats: quantification by arterial spin-labeled MRI and the influence of spin-lattice relaxation time heterogeneity.

Early posttraumatic cerebral hypoperfusion is implicated in the evolution of secondary damage after experimental and clinical traumatic brain injury (TBI). This is the first report of cerebral blood flow (CBF) measurement by continuous arterial spin-labeled magnetic resonance imaging (MRI) early after TBI in rats using the controlled cortical impact (CCI) model. CCI reduced CBF globally at approximately 3 hr (versus normal), with 85% and 49% reductions in a contused cortical region and contralateral cortex, respectively.