12 [22] Otto WR (2002) J. Pathol. 197: 527–535. [23] Jessen KR, Mirsky R (2005) Nat. Rev. Neurosci. 6: 671–682. [24] Nakashima M, Redid AH (2003) Nat. Biotechnol. 21: 1025–1032. [25] Santagati F, Rijli FM (2003) Nat. Rev. Neurosci. 4: 806–818. [26] Savage JJ, Yaden BC, Kiratipranon P, Rhodes SJ (2003) Gene 319: 1–19. [27] Forge A, Wright T (2002) Brit. Med. Bull. 63: 5–24. [28] Panteleyev A, Jahoda CAB, Christiano AM (2001) J. Cell. Sci. 114: 3419–3431. [29] Song C, Gallos LK, Havlin S, Makse HA (2007) J. Stat. Mech: Theory and Experiments P03006. [30] Gallos LK, Song C, Havlin S, Makse HA (2007) Proc. Nat. Acad. Sci. USA , 104: 7746–7751. [31] Athreya KB, Ney PE (2004) Branching processes (Dover Publications). Acknowledgments: We thank B. Bruji´c, B. Dubin-Thaler, H.D. Rozenfeld, S. Havlin, T. Rattei, M. Sigman and A. M. Andrade and J. M. M. Andrade for valuable discussions. This work was supported by National Science Foundation Grants SES-0624116 and EF-0827508. We thank the Brazilian agencies CNPq, CAPES, FAPESB and FUNCAP, and the EU FP7 Neuronano project (NMP4-SL-2008-214547) for financial support