Late prenatal ontogeny of central monoamine neurons in the rat: Fluorescence histochemical observations

摘要: The early ontogeny of the monoamine neuron systems in rat brain has been analysed using Falck-Hillarp fluorescence histochemistry. Serial sagittal sections embryos with a crown rump length between 7 and 13 mm, approximately corresponding to gestational days 12 15 were obtained from mothers treated oxidase inhibitor given order increase levels embryos. 5-hydroxytryptamine (5-HT)-neurons made their first appearance 8 mm embryo, dopamine (DA)-neurons 9 noradrenaline (NA)-neurons 11 embryo. Small, rounded, weakly fluorescent cell bodies forming sparse aggregations appeared first. Fluorescent processes two types soon appeared. Short running perpendicular long axis stem within groups, while slender axon bundles could be traced ascending through met- mesencephalon into prosencephalon as well descending myelencephalon andspinal cord. In embryo primordial DA formation substantia nigra its striatal projections, 5-HT formations caudal mesencephalon, NA neurons are relatively developed. It is concluded that monoamine-neurons develop mechanisms for synthesis storage amines at very stage during ontogeny, thus recapitulating phylogeny these old systems. Likewise, present early. presence neurotransmitters specifying different developing before development nerve terminal areas therefore establishment normal synaptic function may indicate role substances other than transmission impulses.