1. Growth cones detect extracellular signals and guide axons to their targets

3. Membrane signals and topography

4. Flanagan and O’Leary Cell (1996) Elf-1 (ephrinA2) repels anterior (nasal) axons

5. Ephrins and topographic patterning

7. Axon guidance at the midline

8. Trajectory of commisural axons

9. A floorplate chemoattractant guides commisural axons (Tessier-Lavigne and Jessell)

10. Netrin expression in the spinal cord (Serafini and Tessier-Lavigne)

11. Netrin expressed in COS cells attracts commisural axons (Serafini and Tessier-Lavigne)

13. Ventral spinal cord inhibits NGF-dependent sensory axons (Kolodkin and Goodman)

14. Sema 3A expressed in COS cells inhibits NGF-dependent sensory axons (Kolodkin and Goodman)

17. Oriented apical dendrite outgrowth Non-oriented apical dendrite outgrowth E15 embryos Transgenic mice expressing GFP under  -actin promoter The slice overlay assay: a new technique to study apical dendrite patterning. Early postnatal cortical slices Polleux and Ghosh

18. Sema3A is expressed at high levels in the cortical plate during neuronal differentiation Modified from Giger et al. J. Comp. Neurol., 375, 378-92 (1996). VZ SVZ SP IZ 6a CP MZ

19. Guidance of cortical axons by extracellular signals (Polleux and Ghosh)

20. Sema3A repels cortical axons

21. Pyramidal neuron morphology in Sema3A null mice

22. Sema3A is an attractant for cortical dendrites

23. Soluble Guanylate Cyclase co-localizes with MAP2 in the emerging apical dendrite

24. DMSOODQ P3 slice E15 GFP cells 4 div Inhibition of soluble Guanylate Cyclase and PKG disrupts apical dendrite orientation Rp-8-pCPT-cGMPS SQ 22536 Rp-cAMPS 150 microns

25. Guanylate Cyclase Confers Distinct Responses to Axons and Dendrites Sema 3A Guanylate Cyclase

30. A-P guidance in the spinal cord

31. A-P guidance requires a diffusible signal (Zou and Tessier-Lavigne)

32. Role of Wnts in A-P guidance

33. Frizzled-3 is required for A-P guidance

34. Topographic projections from retina to tectum

36. Ephrins are expressed in a posterior-anterior gradient in the tectum (Flanagan, Bohnoeffer)