we have found , by using retrogradely transported fluorescent dyes as either short-term or long-term markers , that occipital cortical neurons which had transiently extended pyramidal tract axons maintain subcortical axonal connections to either the superior colliculus or the pons , and , at least in the case of the corticotectal projection , that the maintained collateral is present prior to the elimination of the transient pyramidal tract collateral .
C0027882
neurons
C0004461
axonal