N. Uesaka et al., “Retrograde Semaphorin Signaling Regulates Synapse Elimination in the Developing Mouse Brain,” Sci 344 (2014): 1020; R. C. Paolicelli et al., “Synaptic Pruning by Microglia Is Necessary for Normal Brain Development,” Sci 333 (2011): 1456; R. Buss et al., “Adaptive Roles of Programmed Cell Death During Nervous System Development,” Ann Rev of Nsci 29 (2006): 1; D. Nijhawan et al., “Apoptosis in Neural Development and Disease,” Ann Rev of Nsci 23 (2000): 73; C. Kuan et al., “Mechanisms of Programmed Cell Death in the Developing Brain,” TINS 23 (2000): 291.