Anatomical evidence demonstrating increased plaques and tangles, cell loss and granulovacuolar degeneration in entorhinal cortex, prepiriform cortex, and the anterior olfactory nucleus, regions involved in the processing of olfactory information, suggested functional impairment in olfaction or olfactory-mediated tasks in patients with Alzheimer's Disease (AD). If there is selective early impact on olfaction or in olfactory-mediated tasks in Alzheimer's Disease, then olfactory deficits may aid in diagnosis as well as in understanding the disease. Since memory impairment is one of the earliest symptoms of Alzheimer's Disease, investigation of olfactory memory seems particularly relevant. Using classical psychophysical techniques, this project has demonstrated impaired olfactory threshold sensitivity and odor memory in AD and has related the impaired olfactory sensitivity to the degree of dementia. The project will continue the longitudinal investigation of 100 AD patients and 100 controls in order to follow these subjects through the progression of the disease process. The current proposal seeks to determine the rate of progression of olfactory dysfunction within individuals with AD and to determine the relationship between olfactory impairment and dementia over the course of time in individuals. Proposed experiments will investigate the impact of the disease on additional olfactory tasks which require varying degrees of cognitive function, in order to determine which tasks signal the greatest degree of olfactory impairment at the earliest point in the disease process. The application also proposes to study olfactory function in Down's Syndrome because of its relationship to Alzheimer's disease and because of preliminary data showing olfactory deficits in Down's patients who have reached the age of 30. Individuals with Down's Syndrome of this age typically show plaques and tangles in the brain similar to Alzheimer's patients. With the aim of understanding the development and progression of olfactory dysfunction in Down's Syndrome, the performance of 20 Down's subjects at 10, 15, 20 and 25 yrs. of age, as well as age-matched and mental age- matched controls, on the same battery of olfactory psychophysical tasks given to the Alzheimer's patients will be assessed. Investigating olfactory dysfunction in Alzheimer's disease and in Down's Syndrome has the potential to contribute to diagnostic accuracy and to understanding Alzheimer's disease. The project will also enhance basic understanding of sensory processing in the human olfactory system.

Agency
National Institute of Health (NIH)
Institute
National Institute on Aging (NIA)
Type
Research Project (R01)
Project #
5R01AG008203-07
Application #
2050100
Study Section
Sensory Disorders and Language Study Section (CMS)
Project Start
1988-08-01
Project End
1998-07-31
Budget Start
1994-08-01
Budget End
1995-07-31
Support Year
7
Fiscal Year
1994
Total Cost
Indirect Cost
Name
San Diego State University
Department
Psychology
Type
Schools of Arts and Sciences
DUNS #
073371346
City
San Diego
State
CA
Country
United States
Zip Code
92182
Olichney, J M; Murphy, C; Hofstetter, C R et al. (2005) Anosmia is very common in the Lewy body variant of Alzheimer's disease. J Neurol Neurosurg Psychiatry 76:1342-7
Moore, Anna Bacon; Bondi, Mark W; Salmon, David P et al. (2005) Eyeblink classical conditioning to auditory and olfactory stimuli: performance among older adults with and without the apolipoprotein E epsilon 4 allele. Neuropsychology 19:437-45
Morgan, Charlie D; Murphy, Claire (2002) Olfactory event-related potentials in Alzheimer's disease. J Int Neuropsychol Soc 8:753-63
Nijjar, Rani K; Murphy, Claire (2002) Olfactory impairment increases as a function of age in persons with Down syndrome. Neurobiol Aging 23:65-73
Wetter, S; Murphy, C (2001) Apolipoprotein E epsilon4 positive individuals demonstrate delayed olfactory event-related potentials. Neurobiol Aging 22:439-47
Murphy, C; Davidson, T M; Jellison, W et al. (2000) Sinonasal disease and olfactory impairment in HIV disease: endoscopic sinus surgery and outcome measures. Laryngoscope 110:1707-10
Murphy, C (1999) Loss of olfactory function in dementing disease. Physiol Behav 66:177-82
Bacon Moore, A S; Paulsen, J S; Murphy, C (1999) A test of odor fluency in patients with Alzheimer's and Huntington's disease. J Clin Exp Neuropsychol 21:341-51
Moore, A B; Murphy, C (1999) A demonstration of classical conditioning of the human eyeblink to an olfactory stimulus. Physiol Behav 66:689-93
Hamilton, J M; Murphy, C; Paulsen, J S (1999) Odor detection, learning, and memory in Huntington's disease. J Int Neuropsychol Soc 5:609-15

Showing the most recent 10 out of 24 publications