TH and sudden infant death syndrome: These authors, in a study on the catecholamine neurons in the brain stem of SIDS victims, reported that TH immunoreactivity was definitely decreased in adrenergic and noradrenergic neurons of the vagal nuclei, locus coeruleus, and area reticularis superficialis ventrolateralis and slightly reduced but not in a significant way in dopaminergic neurons of the SN.