简介：Thedistributionofacetylcholinesterase(AChE)-positivestructuresinthedevelopingratspinalcordwasstudiedwithAChE-histochemistry.AChE-positiveperikaryawerefirstseenonembryonicday14(E14)intheventrolateralportionofthespinalcord.Fromthattimeonward.AChE=containingcellsappearedgraduallyintheintermediategray,dorsalhornandlateralspinalnucleusofthespinalcordinaventral-to-dorsal,andlateral-to-medialorder.Noobviousrostral-to-caudalsequencewasfound.Atbirth,thedistributionpatternofAChE-positiveperikaryawasbasicallysimilartothatinadults.AfterbirthadramaticincreaseintheAChEstainingintensityextendedfrompostnatalday5(P5)topostnatalday21(P21),Inaddition,twophasesoftransientAChEstainingwereobservedintheexternalsurfaceofthedorsalhornfromembryonicday15(E15)toembryonicday21(E21)andinthemarginallayerfromembryonicday21(E21)topostnatalday14(P14),respectively.