Fig. 2

Parvocellular PVN oxytocin neuronal activation following acute MI. Representative photomicrographs of coronal sections of the PVN following a sham or b acute myocardial infarction (MI). Black staining indicates c-Fos-positive nuclei, brown staining indicates oxytocin-positive cytoplasm, and black surrounded by brown staining indicates co-localization of c-Fos protein with oxytocin (yellow arrows). Insets a, b High-power magnification of the dashed-boxes taken from the low magnification micrographs. The bar graphs (mean ± SEM) show the number of: c c-Fos-positive cells, d oxytocin-positive cells, e cells co-localized with oxytocin+c-Fos-protein, and f percentage of oxytocin-positive cells expressing c-Fos protein per section in bilateral parvocellular division of the PVN (pPVN). **P < 0.01 signficant difference between MI rats (n = 8) and sham rats (n = 8; unpaired t-test). Scale bars = 50 μm. 3V third ventricle, pPVN parvocellular paraventricular nucleus