Fig. 5From: Immunomodulatory effects of nicotine on interleukin 1β activated human astrocytes and the role of cyclooxygenase 2 in the underlying mechanismExpression of α7 nicotinic acetylcholine receptor on activated human astrocytes. Human astrocytes grown on chamber slides were incubated with IL-1β and nicotine for 20 h and later fixed in paraformaldehyde for immunohistochemistry. Positively stained cells appear brown in the images. Cells both a untreated and d–f treated with nicotine displayed specific staining for α7nACh receptor protein expression whereas cells stained with b unspecific antibody raised in rat (isotype) and c goat anti-rat (secondary antibody) alone displayed no specific staining. Representative images were taken at ×25 (a–f) and ×40 (g) magnification under the microscopeBack to article page