[Ontogenetic data on the peptidergic interneuronal population in immunoreactivity of the GRF 37 type serum of the human posterolateral hypothalamus. Immunocytochemical studies using anti-GRF 37 and anti-MCH (melanin-concentrating hormone) immune sera].

Human posterolateral hypothalamic neurons are revealed with an anti GRF 37 serum as soon as the 7th week of fetal life. The same neuronal population can be observed in the adult brain even in hypothalami from old subjects, with the same distribution, and similar immunoreactivity than in fetal stages. These neurons are revealed using a melanin concentrating hormone (MCH) antiserum; the MCH immunoreactivity appears at the same stage of fetal development than GRF 37 immunoreactivity. The two antisera recognize two epitopes on one or two molecules. Those new facts agree with an hypothesis about the very important and permanent functional role of that new human hypothalamic interneuronal system.