title: [Histomorphogenesis of spinal ganglia developing on the chorioallantoic membrane].
abstract: The aim of the present research is to study the development of spinal ganglia implanted onto chorio-allantoic membrane (CAM), where they are supplied by 'foreign', extraembryonic vessels. Small blocks including a segment of the neural tube and 4 pairs of somites were isolated from the brachial or thoracic or lumbar region (neuromeres C13 - T1 or T3 - T6 or L1 - L4) of thirty 3-day donor chick embryos and grafted on the CAM of as many 10-day host chick embryos. At regular time intervals after grafting, the implants were fixed, embedded in paraffin, serially cross-sectioned and stained. The preliminary results are similar for the ganglia from the 3 regions: they seem to indicate that in the spinal ganglia grafted on the CAM the developing blood vessels do not exert any morphogenetic influence on the substratum; this corroborates results from previous researches (2) on the normally 'in situ' developing ganglia. It is now the author purpose to submit to a careful analysis a datum from the present research: namely, the earlier appearance of the endoganglionic vessels in the brachial and lumbar grafted ganglia than in the thoracic ones.
mesh_terms: D000482:Allantois; D000818:Animals; D002642:Chick Embryo; D002823:Chorion; D005321:Extraembryonic Membranes; D005727:Ganglia, Spinal / Q000254:growth & development* / Q000637:transplantation; D009024:Morphogenesis
vernacular_title: Analisi dell'istomorfogenesi di gangli spinali che si sviluppano sulla membrana corio-allantoidea.