FOS and pancreatitis: In the brain stem, increased Fos expression was seen bilaterally in the nuclei of cells of the ventrolateral area of the periaqueductal grey and dorsal raphe nucleus in the animals with pancreatitis treated with vehicle (Fig 8B, 28.5 ± 6 cells) or HSV-β-gal (Fig 8C, 40.4 ± 14.8 cells).