Choline acetyltransferase and acetylcholinesterase abnormalities in senile dementia: importance of biochemical measurements in human post-mortem brain specimens

Altered glycosylation of acetylcholinesterase in Creutzfeldt-Jakob disease

Changes in the glycosylation pattern of brain proteins have been associated with Creutzfeldt-Jakob disease (CJD). We have investigated the glycosylation status of acetylcholinesterase (AChE) by lectin binding assay. Our data show that in lumbar CSF from definite and probable sporadic CJD cases AChE activity is lower compared with that in age-matched controls. We also show, for the first time, that AChE glycosylation is altered in CJD CSF and brain. Unlike Alzheimer's disease, in which an alteration in both the glycosylation and levels of AChE molecular forms is observed, the abnormal glycosylation of AChE in CJD appears to be unrelated to changes in molecular forms of this enzyme. These findings suggest that altered AChE glycosylation in CJD may be a consequence of the general perturbation of the glycosylation machinery that affects prion protein, as well as other proteins. The diagnostic potential of these changes remains to be explored.

Neurone loss in the nucleus basalis of Meynert in Creutzfeldt-Jakob disease

In a man of 47 with a 2-month history of Creutzfeldt-Jakob-disease verified neuropathologically a morphometric study of the nucleus basalis of Meynert, the major source of cholinergic innervation of the cortex, revealed a neuronal loss of 45%. The degeneration of these neurones may provide the morphological substrate of the cortical cholinergic deficiency which has been reported in this condition. The six subpopulations of the nucleus basalis were affected in different degrees. Neuronal loss was most pronounced in those subpopulations which project to cortical areas most affected by spongiosis and neuronal loss. It is suggested that maintenance of the nucleus basalis complex is a necessary condition for higher cortical function.