Abstract

The present proposal represents a competitive renewal application. The proposed research focuses on the effects of age on the regulation of activity and functions of the cortical cholinergic afferent system. The research conducted during the previous funding period revealed new insights into the effects of age on the regulation of cortical acetylcholine (ACh) release and attentional abilities. In contrast to the rather limited effects of age per se on cortical ACh release and on attentional functions, our recent experiments on the effects of age in animals with an experimentally-induced partial decrease in the density of cortical cholinergic inputs. While the deafferentiation-induced decrease in baseline cortical ACh release did not differ between young and aged animals, and while stimulated cortical ACh release in young- deafferented animals was identical to that from young-sham-deafferented and aged/sham-deafferented animals, aged/deafferented animals exhibited a strongly attenuated increase in cortical ACh release in response to behavioral and neuropharmacological stimuli. These data suggest that age acted as an intervening variable in deafferented animals, resulting in an age-related attenuation of the capacity of residual cholinergic inputs to the cortex to respond to stimulation. The proposed research will test hypotheses about the neuronal mechanisms mediating the interactions between the effects of aging and partial deafferentation on ACh release, and about the significance of such interactions for the attentional abilities of aged rats. As age-related cognitive disorders may derive from interactions between the effects of age and pre-existing neuropathological processes, and as the decline in cortical cholinergic function remains a primary neuropathological candidate in the development of age-related cognitive disorders, this research will reveal important insights in the neuronal processes underlying the effects of age on the functions of a compromised cortical cholinergic input system.

  Funding Agency

Agency
National Institute of Health (NIH)
Institute
National Institute on Aging (NIA)
Type
Research Project (R01)
Project #
5R01AG010173-08
Application #
6168109
Study Section
Special Emphasis Panel (ZRG1-IFCN-3 (01))
Program Officer
Wagster, Molly V
Project Start
1991-06-01
Project End
2003-03-31
Budget Start
2000-04-01
Budget End
2001-03-31
Support Year
8
Fiscal Year
2000
Total Cost
$245,733
Indirect Cost

  Institution

Name
Ohio State University
Department
Psychology
Type
Schools of Arts and Sciences
DUNS #
098987217
City
Columbus
State
OH
Country
United States
Zip Code
43210

  Publications

Sarter, Martin; Bruno, John P (2004) Developmental origins of the age-related decline in cortical cholinergic function and associated cognitive abilities. Neurobiol Aging 25:1127-39
Herzog, Christopher D; Nowak, Kelly A; Sarter, Martin et al. (2003) Microdialysis without acetylcholinesterase inhibition reveals an age-related attenuation in stimulated cortical acetylcholine release. Neurobiol Aging 24:861-3
Sarter, Martin; Bruno, John P (2002) The neglected constituent of the basal forebrain corticopetal projection system: GABAergic projections. Eur J Neurosci 15:1867-73
Sarter, M; Turchi, J (2002) Age- and dementia-associated impairments in divided attention: psychological constructs, animal models, and underlying neuronal mechanisms. Dement Geriatr Cogn Disord 13:46-58
Burk, Joshua A; Herzog, Christopher D; Porter, M Christine et al. (2002) Interactions between aging and cortical cholinergic deafferentation on attention. Neurobiol Aging 23:467-77
Turchi, J; Sarter, M (2001) Antisense oligodeoxynucleotide-induced suppression of basal forebrain NMDA-NR1 subunits selectively impairs visual attentional performance in rats. Eur J Neurosci 14:103-17
Turchi, J; Sarter, M (2001) Bidirectional modulation of basal forebrain N-methyl-D-aspartate receptor function differentially affects visual attention but not visual discrimination performance. Neuroscience 104:407-17
Sarter, M; Givens, B; Bruno, J P (2001) The cognitive neuroscience of sustained attention: where top-down meets bottom-up. Brain Res Brain Res Rev 35:146-60
Sarter, M; Podell, M (2000) Preclinical psychopharmacology of AIDS-associated dementia: lessons to be learned from the cognitive psychopharmacology of other dementias. J Psychopharmacol 14:197-204
McGaughy, J; Everitt, B J; Robbins, T W et al. (2000) The role of cortical cholinergic afferent projections in cognition: impact of new selective immunotoxins. Behav Brain Res 115:251-63

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