Role of iron in Alzheimer-type dementia in Down Syndrome

The present paper reviews three types of evidence implicating the role of acetylcholine in human memory and dementia: (1) neuropathological evidence that the cholinergic transmitter system is depleted in Alzheimer-type dementia; (2) psychopharmacological studies that have employed “cholinergic blockade” as a model of cholinergic depletion; and (3) clinical studies of cholinergic “replacement” therapy in Alzheimer-type dementia. The evidence that the cholinergic system is depleted in Alzheimer-type dementia has been complemented by the finding that cholinergic blockade in healthy subjects causes a substantial learning (or “acquisition”) deficit in episodic memory. The overall results of studies of replacement therapy have generally been disappointing, but a few have reported benefits in recall and recognition tests. The role of the cholinergic system in many aspects of memory remains to be elucidated; but it seems unlikely that cholinergic depletion accounts for all aspects of the memory disorder in Alzheimer-type dementia, and possibly the depletions of other neurotransmitters also contribute to the memory impairment.

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Role of transcranial Doppler sonography in the differentiation of multi-infarct and Alzheimer-type dementia.

Stroke ◽

10.1161/01.str.25.12.2505 ◽

1994 ◽

Vol 25 (12) ◽

pp. 2505-2507 ◽

Cited By ~ 1

Author(s):

A Alayon Fumero

Keyword(s):

Transcranial Doppler ◽

Doppler Sonography ◽

Transcranial Doppler Sonography ◽

Alzheimer Type ◽

Alzheimer Type Dementia

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Neurochemical Basis of Dementia in Parkinson’s Disease

Canadian Journal of Neurological Sciences / Journal Canadien des Sciences Neurologiques ◽

10.1017/s0317167100046382 ◽

1984 ◽

Vol 11 (S1) ◽

pp. 185-190 ◽

Cited By ~ 36

Author(s):

Oleh Hornykiewicz ◽

Stephen J. Kish

Keyword(s):

Parkinson’S Disease ◽

Parkinson's Disease ◽

Cognitive Impairment ◽

Brain Pathology ◽

Alzheimer Type ◽

Alzheimer Type Dementia ◽

Neuron Function ◽

Additional Role ◽

Choline Acetyltransferase Activity

ABSTRACTAccording to their mental status, patients with Parkinson’s disease can be subdivided into three groups: (1) mentally normal patients; (2) patients with severe cognitive impairment and Alzheimer-type brain pathology (neuritic plaques, neurofibrillary tangles, granulovacuolar changes); and (3) demented patients without any evidence of Alzheimer changes. Neurochemically, irrespective of the presence or absence of Alzheimer-type brain pathology, demented Parkinson patients seem to have the same disturbance of cortical cholinergic neuron function as patients with Alzheimer-type dementia (Alzheimer’s disease), namely, reduced levels of cortical acetylcholine esterase and choline acetyltransferase activity. At present, the question whether the “cortical cholinergic deficiency” is the only (or sufficient) neurochemical basis for the cognitive impairment in Parkinson patients with dementia cannot be answered with certainty; the additional role of other neurotransmitter changes known to occur in the Parkinson brain, especially loss of cortical, hippocampal and subcortical noradrenaline and/or dopamine cannot be ruled out.

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