[Early changes in the microangiogram of the rabbit brain after experimental skull and cerebral trauma. Part 1 methods...

Experiments were performed in order to determine what changes occur in the microcirculation of the brain in animals following closed skull trauma, when these occur in relation to the trauma and what further changes are to be expected. In the first part of the paper suitable experimental methods are described. Skull trauma was inflicted to anaesthetised rabbits by means of a special apparatus by which impact speed, force, frequency, acceleration and period of contact could be determined. Three, five, ten and 15 minutes following the trauma, a special mixture was injected through a catheter in the aortic arch and the animals were decapitated. The brain was sectioned in three anatomically defined places and examined histologically and by microangiography. For the latter purpose glass plate coated with emulsion, a special exposure chamber and an x-ray tube with small focal spot were used. Exposures of five minutes permitted objects of 0.78 micrometers to be sharply resolved. Twenty-one defined areas were enlarged 360 times and compared with histologic sections. The normal microcirculation in the rabbit brain is described.