Premium
Interleukin‐6 is not expressed in activated microglia and in reactive astrocytes in response to lesion of rat basal forebrain cholinergic system as demonstrated by combined in situ hybridization and immunocytochemistry
Author(s) -
Lemke Rainer,
Härtig Wolfgang,
Roßner Steffen,
Bigl Volker,
Schliebs Reinhard
Publication year - 1998
Publication title -
journal of neuroscience research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.72
H-Index - 160
eISSN - 1097-4547
pISSN - 0360-4012
DOI - 10.1002/(sici)1097-4547(19980115)51:2<223::aid-jnr11>3.0.co;2-9
Subject(s) - basal forebrain , cholinergic neuron , cholinergic , nucleus basalis , in situ hybridization , choline acetyltransferase , biology , neuroscience , immunocytochemistry , forebrain , lesion , pathology , central nervous system , endocrinology , medicine , gene expression , biochemistry , gene
Interleukin‐6 may play an essential role in early inflammatory processes as response to degenerating cholinergic cells in the nucleus basalis of Meynert in patients suffering Alzheimer's disease. The cholinergic immunotoxin, 192IgG‐saporin, was applied to produce selective and specific degenerations of basal forebrain cholinergic cells. To disclose the lesion‐induced temporal cascade of the expression pattern of IL‐6, and to reveal the cellular source for production and secretion of IL‐6 in vivo after endogeneously induced basal forebrain cholinergic cell loss, both in situ hybridization and immunocytochemistry for IL‐6 were performed. To identify the cell types expressing IL‐6 mRNA, double labeling techniques were applied combining in situ hybridization technique with immunocytochemistry and lectin histochemistry for both micro‐ and astroglia and a number of neuronal markers including choline acetyltransferase, parvalbumin, and neurofilaments. In the intact brain, IL‐6 is mainly localized in neurons, in particular in both cholinergic and GABAergic neurons of the basal forebrain. Although basal forebrain cholinergic lesion resulted in a dramatic increase in the number of micro‐ and astroglial cells at the lesion site, IL‐6 expression could not be detected in any of the lesion‐induced activated glial cell types. Moreover, cholinergic lesion led to a reduced number of IL‐6‐expressing cells in the basal forebrain, which is assumed to be due to the loss of cholinergic cells. The predominantly neuronal localization in rat brain suggests a role for IL‐6 in activating micro‐ and astroglial cells in response to degenerating cholinergic neurons. J. Neurosci. Res. 51:223–236, 1998. © 1998 Wiley‐Liss, Inc.