Abstract
Transection of the brain stem is thought to be concerned with the following two events. One is to cut pathways on which the streams of ascending and descending impulses are conducted, and the other is to divide the reticular formation into two parts, from one of which an energizing stream goes up, and from the other of which a controlling stream goes down so that the internal environment of the whole body, including the brain, may have a suitable level of activity.
The position of transection has an important significe in the first one. However it is far more significant in the second one, because the proximal surface of the transected reticular formation determines the level of energizing stream and the distal surface does the level of the controlling mechanism.
Whence the width of the transection should be as narrow as possible; Needles to mention, in the operation any other effects should be prevented which might disturb the experiment, and the transection should be easily and repeatedly reproducible at any proposed levels.
From the above point of view, a new stereotaxic method of transection was designed. The method and some experiences of the operation were stated in comparison with those of the other operations. A few data on the transected surfaces were added.
