Three-dimensional reconstruction of the rat brain cortical microcirculation in vivo.
We used confocal laser scanning microscopy (CLSM) to investigate the morphology and three-dimensional relationships of the microcirculation of the superficial layers of the rat brain cortex in vivo. In anesthetized rats equipped with a closed cranial window (dura mater removed), after i.v. injection of 3 mg/100 g of body weight of fluorescein in 0.5 ml of saline, serial optical sections of the brain cortex intraparenchymal microcirculation were taken. Excitation was at a wavelength of 488 nm (argon laser), and emission was collected above 515 nm. CLSM provided images of brain vessels with sufficient signal-to-noise ratio for three-dimensional reconstructions down to a depth of 250 microns beneath the surface of the brain. Compared to conventional fluorescence microscopy, CLSM has a much higher axial resolution and higher depth of penetration. Laser light-induced intravascular aggregates, irregularities of erythrocyte flow, or microvascular occlusions ("light and dye injury") were not apparent in the current experimental paradigm. CLSM is a promising new tool for in vivo visualization of the cerebral microcirculation. Future studies have to characterize the potential damage to the tissue dye mechanisms.
Dirnagl
U
U
Department of Neurology, University of Munich, Germany.
Villringer
A
A
Gebhardt
R
R
Haberl
R L
RL
Schmiedek
P
P
Einhäupl
K M
KM
D000818:Animals; D002196:Capillaries / Q000033:anatomy & histology; D002540:Cerebral Cortex / Q000098:blood supply*; D007091:Image Processing, Computer-Assisted; D008297:Male; D008833:Microcirculation / Q000033:anatomy & histology*; D008853:Microscopy / Q000379:methods; D008856:Microscopy, Fluorescence; D010296:Parietal Lobe / Q000098:blood supply; D010841:Pia Mater / Q000098:blood supply; D051381:Rats; D011919:Rats, Inbred Strains; D013346:Subarachnoid Space / Q000098:blood supply