Expression of gamma-aminobutyric acid immunoreactivity in reactive astrocytes after ischemia-induced injury in the adult forebrain.
Transient ischemia induces an increase in glial fibrillary acidic protein (GFAP) immunoreactivity which can be detected in specific forebrain regions of the adult gerbil as early as day 2, becomes prominent by day 4-7 and persists for at least 3 months. These forebrain areas include layers 2/3 of the somatosensory and auditory cortices, the CA1 and CA4 sectors of the hippocampus, the dorsolateral region of the striatum, and the dorsolateral subregion of the medial septal nucleus. In addition, astrocytes in the ischemically lesioned areas stain with gamma aminobutyric acid (GABA) antiserum. These GABA-immunoreactive astrocytes are not found in non-damaged areas. The time-course of expression of GABA immunoreactivity is similar to that of GFAP immunoreactivity. Using a double immunofluorescent staining method, reactive astrocytes which express GABA immunoreactivity were also found to immunostain with either GFAP or vimentin. On the other hand, astrocytes were not found to be immunoreactive with antibodies to glutamic acid decarboxylase or glutamate. Our present finding demonstrates, in an in vivo model, an aberrant expression of GABA immunoreactivity by astrocytes which is not observed in non-ischemic adult animals.
Lin
R C
RC
Department of Physiology and Biophysics, Hahnemann University, Philadelphia, PA 19102.
Polsky
K
K
Matesic
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DF
D000818:Animals; D000911:Antibodies, Monoclonal; D001253:Astrocytes / Q000378:metabolism* / Q000473:pathology; D005260:Female; D005849:Gerbillinae; D005904:Glial Fibrillary Acidic Protein / Q000032:analysis; D006624:Hippocampus / Q000378:metabolism* / Q000473:pathology; D007150:Immunohistochemistry; D002546:Ischemic Attack, Transient / Q000378:metabolism* / Q000473:pathology; D008297:Male; D016548:Prosencephalon / Q000378:metabolism* / Q000473:pathology; D014746:Vimentin / Q000032:analysis; D005680:gamma-Aminobutyric Acid / Q000032:analysis / Q000378:metabolism*
D000911:Antibodies, Monoclonal; D005904:Glial Fibrillary Acidic Protein; D014746:Vimentin; D005680:gamma-Aminobutyric Acid