Morphological Assessment of Microcirculation - Animal Models of Acute Neurological Injuries: Injury and Mechanistic Assessments - page 473

Fig. 4. ( a ) In carbon black injection method, microvessels at the cerebral cortex can be observed (coronal section of
cerebral cortex) ( arrowheads : intraparenchymal arterioles). ( b ) Coronal section of microangiography of microvessels at
the cerebral cortex ( arrowheads : intraparenchymal arterioles). ( c ) Not only microvessels but also major arteries can be
evaluated (anteroposterior view of the pons) ( arrowheads : basilar artery).
the perfusion-fi xation. After injection, the animal is kept in
a freezer for several hours in order to promote solidifi ca-
tion of a solution with gelatin. After that, the brain is
removed and kept in the fi xative solution used as perfusion
fi xative solution for 1 or 2 weeks. The brain is cut at 2 mm
to several centimeters and the contact microangiogram is
taken using an ultrasoft X-ray apparatus at 40-60 V and
4-5 mA for 8-12 min on the Softex fi lm.
4. Notes
1. In casting method, how to avoid polymerization of polyester
resin during injection?
The fi rst step is to adjust the mixture ratio of resin and catalyst.
The polymerization period can be extended by the use of very
low concentration of catalyst; however, it results in incomplete
polymerization of resin. Extension of polymerization period
with enough concentration of catalyst can be achieved by per-
fusion with cool solution just before the infusion of polyester
resin.
2. In carbon black infusion and microangiography, how to avoid
too early hardening of gelatin mixed solution?
The fi rst step is to adjust the concentration of gelatin; however,
very low concentration of gelatin results in incomplete harden-
ing of solution. Extension of hardening period with enough
concentration of gelatin can be achieved by perfusion with
warm solution (45 C) just before the infusion of gelatin
solution.