R. Ferrari et al., Subunit and region-specific decreases in nicotinic acetylcholine receptor mRNA in the aged rat brain, NEUROBIOL A, 20(1), 1999, pp. 37-46
We have investigated possible changes in the mRNA levels for several alpha
and beta subunits of the nicotinic acetylcholine receptor (nAChR) and the l
evel of binding for nicotinic ligands in 7- to 32-month-old rats. alpha 4 a
nd beta 2, and to a lesser extent alpha 6 and beta 3, mRNA levels showed de
creases between 20 and 30% at 29 months of age which in some areas reached
50% at 32 months of age, alpha 7 showed a small increase from 7 to 14 month
s and then a progressive decrease from 14 to 32 months down to the 7-month
levels. H-3-epibatidine binding did not significantly change from 7 to 32 m
onths of age in rat tel- and diencephalon. Binding in the substantia nigra
was exceptional in that it showed a significant decrease starting from 23 m
onths of age. I-125-alpha-bungarotoxin binding showed a pattern of change w
hich roughly paralleled that of alpha 7 mRNA. These findings show that an a
lteration in some steps of nAChR biosynthesis takes place during aging, whi
ch may be related to functional changes in nicotinic transmission. (C) 1999
Elsevier Science Inc. All rights reserved.