in the brainstem , large amounts of grains were found in the ventrolateral division of the periaqueductal gray , in the locus coeruleus , in the nucleus tractus spinalis nervi trigemini and in the raphe obscurus , pallidus and magnus , while a widespread and lower grain density was observed in the reticular formation .
C0006121
brainstem
C0023951
locus coeruleus