Journal Article

Dorsomedial SCN neuronal subpopulations subserve different functions in human dementia

David G. Harper, Edward G. Stopa, Victoria Kuo-Leblanc, Ann C. McKee, Kentaro Asayama, Ladislav Volicer, Neil Kowall and Andrew Satlin

in Brain

Published on behalf of The Guarantors of Brain

Volume 131, issue 6, pages 1609-1617
Published in print June 2008 | ISSN: 0006-8950
Published online March 2008 | e-ISSN: 1460-2156 | DOI: http://dx.doi.org/10.1093/brain/awn049
Dorsomedial SCN neuronal subpopulations subserve different functions in human dementia

Show Summary Details

Preview

The suprachiasmatic nuclei (SCN) are necessary and sufficient for the maintenance of circadian rhythms in primate and other mammalian species. The human dorsomedial SCN contains populations of non-species-specific vasopressin and species-specific neurotensin neurons. We made time-series recordings of core body temperature and locomotor activity in 19 elderly, male, end-stage dementia patients and 8 normal elderly controls. Following the death of the dementia patients, neuropathological diagnostic information and tissue samples from the hypothalamus were obtained. Hypothalamic tissue was also obtained from eight normal control cases that had not had activity or core temperature recordings previously. Core temperature was analysed for parametric, circadian features, and activity was analysed for non-parametric and parametric circadian features. These indices were then correlated with the degree of degeneration seen in the SCN (glia/neuron ratio) and neuronal counts from the dorsomedial SCN (vasopressin, neurotensin). Specific loss of SCN neurotensin neurons was associated with loss of activity and temperature amplitude without increase in activity fragmentation. Loss of SCN vasopressin neurons was associated with increased activity fragmentation but not loss of amplitude. Evidence for a circadian rhythm of vasopressinergic activity was seen in the dementia cases but no evidence was seen for a circadian rhythm in neurotensinergic activity. These results provide evidence that the SCN is necessary for the maintenance of the circadian rhythm in humans, information on the role of neuronal subpopulations in subserving this function and the utility of dementia in elaborating brain–behaviour relationships in the human.

Keywords: circadian rhythm; Alzheimer's disease; vasopressin; neurotensin; neurodegeneration

Journal Article.  5902 words.  Illustrated.

Subjects: Neurology ; Neuroscience

Full text: subscription required

How to subscribe Recommend to my Librarian

Users without a subscription are not able to see the full content. Please, subscribe or login to access all content.