Absence of adrenergic neurons in nucleus tractus solitarius in sudden infant death syndrome.

Immunohistochemical study of catecholamine synthesizing enzymes tyrosine hydroxylase (TH) and phenylethanolamine-N-methyl transferase (PNMT) was performed in lower brain stem of 5 controls and 9 sudden infant death "syndrome" (SIDS) cases. No difference was noticed in TH immunoreactive neuronal groups. With anti-PNMT antibody, electively in nucleus gelatinosus (NG), a subnucleus of nucleus tractus solitarius, an absence of immunoreactivity was noticed. Catecholamine neuronal cell bodies in NG were present. The discussion favours a nonartefactual interpretation of data. A delay in maturation would be a possible explanation.