RT Journal
A1 Davis KL, Marin D, Purohit DP, et al
T1 CHolinergic markers in alzheimer disease—reply
JF JAMA
JO JAMA
YR 1999
FD December 15
VO 282
IS 23
SP 2208
OP 2209
DO 10-1001/pubs.JAMA-ISSN-0098-7484-282-23-jbk1215
UL http://dx.doi.org/10-1001/pubs.JAMA-ISSN-0098-7484-282-23-jbk1215
AB 
Bartus and Emerich also point to the plethora of experiments in animal
model systems (some of which have been contributed by our group), showing
that deficits in forebrain cholinergic systems can result in significant learning
and memory deficits. Although some studies have questioned the validity of
these findings,1- 2 we agree
that manipulations that adversely affect the forebrain cholinergic system
can impair learning, memory, and cognition. However, this fact cannot be interpreted
to mean that all cognitive deficits result from forebrain cholinergic system
dysfunction. It is quite possible that the dysfunction in early AD has its
origin in something other than the cholinergic system. The contention that
it is possible that cholinergic system deficits occur in AD "well in advance
of the death of cholinergic neurons" is a hypothesis that must be tested.
That such a state in animal model systems can produce cognitive deficits does
not obligate it to occur in AD, and the results of our studies, although not
definitive in this regard, cast doubt about this contention.