Tyrosine hydroxylase-like immunoreactivity in senile plaques is not related to the density of tyrosine hydroxylase-positive fibers in patients with Alzheimer's disease.
The numbers of silver-stained senile plaques and plaques containing tyrosine hydroxylase (TH)-like immunoreactivity were counted in the neocortex, amygdala and hippocampus of control subjects and patients with Alzheimer's disease, and compared with the density of TH-positive nerve fibers. The number of silver-stained senile plaques was lowest in the hippocampus and highest in the amygdala, and increased in all three structures in relation to the degree of dementia in the patients. A small proportion of plaques in the hippocampus of the most demented subjects and a large proportion of plaques in the amygdala were TH-positive. No TH-like immunoreactivity was found in plaques in the neocortex, although this structure contained almost as many silver-stained senile plaques and was as densely innervated by TH-positive fibers as the amygdala. The number of plaques containing TH-like immunoreactivity was, therefore, not proportional to the innervation of the structures by TH-positive fibers, nor to the total number of plaques in the structure, suggesting that the dissociation between the proportion of TH-positive plaques in the amygdala and neocortex may be due to differences in the populations of TH-positive fibers innervating the structures.
Cervera
P
P
INSERM U. 289, Hôpital de la Salpêtrière, Paris, France.
Duyckaerts
C
C
Ruberg
M
M
Hirsch
E
E
Ransmayr
G
G
Hauw
J J
JJ
Agid
Y
Y
D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000201:enzymology* / Q000473:pathology; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D014446:Tyrosine 3-Monooxygenase / Q000378:metabolism*
D014446:Tyrosine 3-Monooxygenase