Synaptic loss reflected by secretoneurin-like immunoreactivity in the human hippocampus in Alzheimer's disease.
Secretoneurin is a recently described peptide derived by endoproteolytic processing from secretogranin II, previously named chromogranin C. In this study, we have investigated the distribution of secretoneurin-like immunoreactivity in the human hippocampus in controls and in Alzheimer's disease patients, and compared the staining pattern to that of calretinin. Secretoneurin-like immunoreactivity is present throughout the hippocampal formation. At the border of the dentate molecular layer and the granule cell layer, a band of dense secretoneurin immunostaining appeared. In this part, as in the area of the CA2 sector, the high density of secretoneurin-immunoreactivity coincided with calretinin-like immunoreactivity. The mossy fibre system displayed a moderate density of secretoneurin-immunoreactivity. In the entorhinal cortex, a particularly high density of secretoneurin-immunoreactivity was observed. The density of secretoneurin-like immunoreactivity was significantly reduced in the innermost part of the molecular layer and in the outer molecular layer of the dentate gyrus in Alzheimer's disease. For calretinin-like immunoreactivity, a less pronounced decrease was found in the innermost part of the molecular layer. About 40-60% of neuritic plaques were secretoneurin-immunopositive. This study shows that secretoneurin is distinctly distributed in the human hippocampus and that significant changes of secretoneurin-like immunoreactivity occur in Alzheimer's disease, reflecting synaptic loss.
Kaufmann
W A
WA
Clinic of Psychiatry, Innsbruck, Austria.
Barnas
U
U
Humpel
C
C
Nowakowski
K
K
DeCol
C
C
Gurka
P
P
Ransmayr
G
G
Hinterhuber
H
H
Winkler
H
H
Marksteiner
J
J
D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000378:metabolism* / Q000473:pathology*; D064032:Calbindin 2; D018728:Entorhinal Cortex / Q000378:metabolism / Q000473:pathology; D005260:Female; D006624:Hippocampus / Q000378:metabolism* / Q000473:pathology*; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D009419:Nerve Tissue Proteins / Q000378:metabolism; D009479:Neuropeptides / Q000378:metabolism*; D016612:Paraffin Embedding; D064030:S100 Calcium Binding Protein G / Q000378:metabolism; D053381:Secretogranin II; D013569:Synapses / Q000473:pathology*
C576764:CALB2 protein, human; D064032:Calbindin 2; D009419:Nerve Tissue Proteins; D009479:Neuropeptides; D064030:S100 Calcium Binding Protein G; D053381:Secretogranin II; C081159:secretoneurin