Sl. Ding et Aj. Elberger, A MODIFICATION OF BIOTINYLATED DEXTRAN-AMINE HISTOCHEMISTRY FOR LABELING THE DEVELOPING MAMMALIAN BRAIN, Journal of neuroscience methods, 57(1), 1995, pp. 67-75
Biotinylated dextran amine (BDA) has proven to be an excellent anterog
rade tracer in adult mammalian brains, having some advantages over oth
er anterograde tracers such as Phaseolus vulgaris-leucoagglutinin (PKA
-L) and biocytin. However, results are inferior when BDA is used in ne
onatal mammals. To improve the sensitivity and quality of BDA labeling
in neonatal mammalian brains, the tetramethylbenzidine-sodium tungsta
te (TMB-ST) method for horseradish peroxidase (HRP) histochemistry was
modified and used in BDA histochemistry; After BDA application to the
visual cortex of neonatal rat and cat, contralateral and ipsilateral
cortical and subcortical regions were examined for BDA-labeled axons a
nd terminals. The modified BDA histochemistry produced corpus callosum
(CC) axons in neonatal rat and cat that were heavily and continuously
labeled. The distribution, trajectories, branching and termination of
individual CC axons, and even possible axon-axon contacts, were clear
ly identified in exquisite detail, even at low magnification. The qual
ity of BDA labeling in the ipsilateral lateral geniculate nucleus and
superior colliculus was similar to that of the CC axonal labeling. The
se results indicate that the modified BDA histochemistry provides a ve
ry sensitive and reliable approach to revealing the detailed distribut
ion and morphology of projecting axons and terminals in the developing
mammalian nervous system.