S. Wetter et C. Murphy, Apolipoprotein E epsilon 4 positive individuals demonstrate delayed olfactory event-related potentials, NEUROBIOL A, 22(3), 2001, pp. 439-447
Apolipoprotein E epsilon4 positive individuals have deficits in the ability
to identify and remember odors, as demonstrated by psychophysical measures
of olfactory function. The purpose of the present study was to identify ol
factory deficits in this population using an objective electrophysiological
measure: the olfactory event-related potential (OERP). Olfactory and audit
ory ERPs were recorded from the Fz, Ct, and Pt electrode sites in 10 epsilo
n4 positive individuals and 10 age and gender-matched epsilon4 negative ind
ividuals in a single-stimulus paradigm. The results indicate: (1) individua
ls who are positive for the apolipoprotein E epsilon4 allele demonstrated d
elays (of approximately 100 ms) in the processing of olfactory information
compared to those who are epsilon4 negative; (2) OERP latency is more sensi
tive than psychophysical measures of olfactory function; (3) delays in the
cognitive P3 component of the OERP are associated with deficits in the abil
ity to identify an odor; and (4) unlike the moderate ranges found in audito
ry ERP, OERP latency showed high sensitivity and specificity in classifying
epsilon4 positive and negative individuals. (C) 2001 Elsevier Science Inc.
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