Slit Branches Out

Science's STKE  08 Jan 2002:
Vol. 2002, Issue 114, pp. tw8
DOI: 10.1126/stke.2002.114.tw8

The secreted proteins of the Slit family have been characterized as chemorepellents that regulate axon guidance and neuronal migration. However, they also stimulate branching of dorsal root ganglion axons. Whitford et al. now show that Slit stimulates branching of cortical neuronal dendrites as well. Slit and its receptor Robo are expressed during the time when the migrating patterns of neurons and axons are elaborating the layers of the cerebral cortex. As expected, exogenously added and endogenously expressed Slit repelled axons of cultured cortical neurons. However, Slit stimulated the total number of neuronal dendrites and dendritic branch points, as well as dendritic length. Expression of a dominant negative Robo receptor inhibited the stimulatory effect of Slit on dendrites. Hence, branch formation may be a general property of Slit, making these secreted proteins bifunctional chemotropic cues that differentially regulate axonal and dendritic patterning in the developing mammalian brain.

K. L. Whitford, V. Marillat, E. Stein, C. S. Goodman, M. Tessier-Lavigne, A. Chedotal, A. Ghosh, Regulation of cortical dendrite development by Slit-Robo interactions. Neuron 33, 47-61 (2001). [Online Journal]