The fate of the large striatal interneurons expressing calretinin in Huntington's disease.
Huntington's disease (HD) is characterized by the atrophy of the striatum due to losses of projection neurons, while interneurons are relatively spared. However, little is known about the fate of the large interneurons that express calretinin (Cr) in HD. We addressed this issue by applying a double immunofluorescent labeling technique to postmortem striatum from HD patients and controls. We compared the distribution and density of Cr-positive (+) interneurons and their degree of choline acetyltransferase (ChAT) coexpression in normal and HD cases. Large interneurons containing only Cr, ChAT, or both occurred in the normal human striatum and a twofold decrease in the density of Cr+/ChAT+ and Cr-/ChAT+ neurons was recorded in HD striatum compared to controls. However, studies undertaken with neurokinin-1 receptor as a marker of large Cr+ and ChAT+ neurons revealed that these neurons are selectively spared in HD. Hence, the apparent decrease in the number of Cr+/ChAT+ and Cr-/ChAT+ neurons in HD is better explained by a diminution in the expression of Cr and ChAT than by the degeneration of these cells. Altogether, our data suggest that neurodegenerative processes at play in HD affect the expression of Cr and ChAT in the large striatal interneurons without causing their death.
Massouh
Mireille
M
Centre de recherche Université Laval Robert-Giffard 2601, Chemin de la Canardière, Local F-6500 Beauport, Québec, Canada, G1J 2G3.
Wallman
Marie-Josée
MJ
Pourcher
Emmanuelle
E
Parent
André
A
D000328:Adult; D064032:Calbindin 2; D002452:Cell Count / Q000379:methods; D002795:Choline O-Acetyltransferase / Q000378:metabolism; D003342:Corpus Striatum / Q000473:pathology*; D005260:Female; D006801:Humans; D006816:Huntington Disease / Q000473:pathology*; D007395:Interneurons / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D018040:Receptors, Neurokinin-1 / Q000378:metabolism; D064030:S100 Calcium Binding Protein G / Q000378:metabolism*
C576764:CALB2 protein, human; D064032:Calbindin 2; D018040:Receptors, Neurokinin-1; D064030:S100 Calcium Binding Protein G; D002795:Choline O-Acetyltransferase