Fos expression in tyrosine hydroxylase-containing neurons in rat brainstem after visceral noxious stimulation: an immunohistochemical study

Figure 3 Photomicrographs showing the distribution and morphological characteristics of TH-ir neurons (arrowheads), Fos-ir neurons (arrows) and TH/Fos double-labeled neurons (double arrowheads) in SOL (a, a’ and b, b’), RVL (c, c’ and d, d’) and LC (e, e’ and f, f’). a, a’, c, c’ and e, e’ were taken from visceral noxious stimulating rats, while b, b’, d, d’ and f, f’ were taken from subcutaneous noxious stimulating rats, respectively. a, b, c, d, e and f are lower magnification photomicrograph (original magnification × 100). a’, b’, c’, d’, e’ and f’ are higher magnification photomicrograph (original magnification × 1000) of the rectangle in a, b, c, d, e and f, respectively. Abbreviations: 4V: The fourth ventricle. cc: Central canal. LC: Locus coeruleus. LRT: Lateral reticular nucleus. RVL: Rostroventrolateral reticular nucleus. sol: Solitary tract. SOL: Solitary tract nucleus.