The Missing Chain

An article by Sanai et al. (2011) published in Nature set the disappearance of the rostral migratory stream (RMS) in humans around the 18th month after birth. In their comment on this article, Arellano and Rakic (2011) underline the limits of adult neurogenesis and put the attention on a branch of this stream reaching the ventro-medial prefrontal cortex, defined as “a feature that has not been described in any non-human mammal after birth” (Arellano and Rakic, 2011). We previously published three papers showing chains of neuroblasts reaching the frontal cortex of postpuberal rabbits (6–12 months) from the RMS (Luzzati et al., 2003, 2006; Ponti et al., 2006). We called these streams “parenchymal chains” since they migrate through the corpus callosum to enter the cortical gray matter (Figure 1). In their comment entitled “Going with the wean,” dealing with an article published in the megahit journal Nature, Arellano and Rakic quote a famous blockbuster movie. In The missing chain