Immunohistochemical study of the catecholaminergic systems in the lower brain stem of the human infant

The study of catecholaminergic (CA) systems in the lower brain stem was undertaken in the infant. A method of indirect immunohistofluorescence using antibodies to tyrosine-hydroxylase (TH) was applied to five brains from infants whose deaths had no neurological cause; two brains were submitted to fully systematic investigation. A topographical and morphocytological analysis of the CA systems was carried out on horizontal serial sections. A neuronal map is shown presenting four bulbar and four pontine sections. The disposition of the main CA groups (i.e. A1, A2, locus coeruleus) was found to be consistent with the data provided by the literature concerning the human foetus and the adult. Topographic differences and peculiarities are emphasized in the infant. Mapping of phenylethanolamine N methyltransferase (PNMT) positive neurons was performed in one plane of section of mid-medulla. This technique might usefully be applied to the exploration of putative diseases of bulbopontine CA systems, such as the sudden infant death syndrome and central blood pressure disorders.