The animals were sacrificed by quick decapitation without any initial stress. The dissection for separating the cerebral cortex, corpus striatum, hypothalamus and hippocampus of the brain was carried out by the method described by Glowinski and Iverson . Special care was taken to avoid damage or irritation of the tissues of any part of the brain while removing from the skull or while dissecting out the different areas.
The tissues of regions from one half of the brain were used for ACh assay and those in regions from other half were selected to determineAChE activity. To avoid the influence of dominant half of the brain and the differences between ACh content or AChE activity in right and left halves of brain, the following procedure was adopted. From 50% of the rats in each group, the regions from right half of the brain were selected for ACh assay. The regions of left half were taken
to determine AChE activity; and vice versa from remaining 50% of the rats.