Quantitative mapping analyzer for determining the distribution of neurochemicals in the human brain

We developed a human brain mapping analyzer to determine the quantitative d istribution of specific molecules, such as neurotransmitters or neuromodula tors, based on a fluorescence microphotometry system that we had previously developed. The immunohistochemical fluorescence emitted from each microare a of a brain slice is collected into a photomultiplier tube through the pin hole and objective lens of a microscope. The brain slice is moved in the x- or y-direction by a motorized scanning stage under the objective lens, and the fluorescence intensities are measured quantitatively. The scanning spe ed is approximately 100 microareas/s, the maximum stage motion is 150 x 150 mm, and an unlimited amount of data can be gathered continuously by transf er to external memory devices. In this paper, this analyzer is characterize d in detail, and the methods used for the preparation and analysis of human brain slices are described. As an example, the cholinergic distribution in hemispheric coronal slices of the adult human brain is analyzed. Each slic e, immunohistochemically stained for choline acetyltransferase, was divided into approximately 3 million microareas (one area is 50 mu m in diameter), and the distribution of the cholinergic neurons is shown. (C) 1998 Elsevie r Science B.V. All rights reserved.