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Intralaminar Neurochemical Distributions in Human Midtemporal Cortex: Comparison Between Alzheimer's Disease and the Normal
Author(s) -
Perry Elaine K.,
Atack John R.,
Perry Robert H.,
Hardy John A.,
Dodd Peter R.,
Edwardson James A.,
Blessed Garry,
Tomlinson Bernard E.,
Fairbairn Andrew F.
Publication year - 1984
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.1984.tb02801.x
Subject(s) - choline acetyltransferase , acetylcholinesterase , glutamate decarboxylase , neurochemical , glutamate receptor , cholinergic , cerebral cortex , amino acid , biochemistry , alzheimer's disease , white matter , biology , glutamic acid , medicine , endocrinology , enzyme , chemistry , disease , receptor , radiology , magnetic resonance imaging
The intralaminar distributions of transmitter and nontransmitter enzyme activities and amino acid levels were determined in the midtemporal cortices from normal individuals and established cases of Alzheimer's disease. In the normal, choline acetyltransferase (CAT) and acetylcholinesterase (AChE) activities were relatively high in the outer cortical layers, particularly, for CAT, in the two granular layers (II and IV). Both activities were reduced in Alzheimer's disease at all, although generally most extensively in the outer and middle layers of the gray matter whereas activities were near normal in the white matter. Further, the enzyme distribution patterns of these cholinergic activities were also disrupted in Alzheimer's disease and the activity of CAT throughout the cortex was generally reduced to that found in the white matter. No such differences in distribution were found for two other enzymes, pseudocholin‐esterase and lactate dehydrogenase. Assessment of the γ‐aminobutyric acid (GABA) system in the normal revealed a much more extensive intralaminar variation in the enzyme, glutamate decarboxylase, compared with the level of GABA itself. In contrast with the cholinergic enzymes, neither the levels nor intralaminar patterns of GABA were altered in Alzheimer's disease. From an analysis of free amino acids at the different cortical levels, the cortical pattern of glutamic acid in the normal was different from that for GABA, asp artic acid, or non‐transmitter amino acids such as alanine. Neither of the putative amino acids, glutamate or aspartate, was altered in Alzheimer's disease. These findings demonstrate the relatively selective nature of micro chemical changes oc‐curing in the cortex in Alzheimer's disease and suggest that a functional abnormality in cholinergic input to the outer neocortical layers (I‐IV) with predominantly receptive and associative functions may be an important feature of the disease.