1. Les power point sont sur le site du Master BS, dans l’onglet de l’UE FMBS106
Guidage axonal - Développement du cerveau - Remodelage neuronal - Mémoire

2. 1) Attraction by the midline
2) Crossing the midline
3) Molecular changes before and after the crossing
4) AC or PC ? (DRL/WNT5)
5) Fasciculation
Book chapter
Navigating intermediate targets: the nervous system midline
Dickson and Zou in Cold Spring Harbor Perspect Biol 2010
(Neuronal guidance - the biology of brain wiring)

3. Commissural axons at the midline in vertebrates and Drosophila

4. Morphogens involved in neuronal guidance and their receptors

5. Netrins, Slits and their receptors.
Receptor for attraction (DCC)
Receptors for repulsion
(UNC5 for Netrins; Robo for Slits)

6. Guidance-cue receptor signaling
strategies.

7. Mutipe guidance cues
control the pathfinding
of spinal cord commissural
axons along the dorso-ventral axis

8. Midline crossing mutants in
Drosophila
Fig in Development of
the nervous system (book)

9. Molecular cues controlling the pathway choices at the Drosophila midline:
COMM regulates ROBO1 trafficking and midline crossing

10. Molecular cues controlling the pathway choices at the vertebrate midline:
the Slit/Robo and Sema3B, 3F/Neuropilin2
systems control midline guidance

11. Drosophila ventral nerve cord
A Robo code for lateral
positioning
Rodent spinal cord

12. DRL/WNT5 in the Drosophila brain:
Grillenzoni et al., Development 2007
Mamalian Ryks in the developing nervous system:
Fradkin et al., Trends in Neurosciences 2010

13. The mushroom bodies (MBs) in the adult Drosophila brain
Rein et al., 2002 Current Biology

14. A wild-type  neuron  vertical branch  horizontal branch midline
10mm
10mm
 vertical branch
 horizontal branch
midline
Srausfeld et al., MRT 2003
10mm
10mm

15. The drl Receptor Tyrosine Kinase
Fradkin et al., TINS 2010

16. DRL is not expressed in the MBs (FASII)

17. DRL is not expressed in the MBs (FASII)

18. DRL in the embryonic brain

19. drl LOF mutation induces no apparent defects in the embryonic brain
but do induce defects in the embryonic nerve cord

20. drl is not expressed in the MB neurons but is
required for the MB development
Grillenzoni et al., Development 2007

21. -/- -/- -/- +/- mutant phenotype mutant phenotype ? cell-autonomous ?
MARCM clones
-/-
-/-
-/-
+/-
mutant phenotype
mutant phenotype ?
cell-autonomous ?

22. -/-
-/-
mutant phenotype

23. +/+
-/-
+/+
+/-
No mutant phenotype, therefore
non cell-autonomous

24. Wnt5-/Y; -GAL4 UAS-mGFP/+
UAS-Wnt5/+
Conclusions:
Wnt5 is necessary for the axonal growth
in an intrinsic manner

25. A growing b axon Secreted Transmembrane receptor protein b axon axonal
WNT5
axonal
growth ?
Transmembrane
receptor
Secreted
protein

26. A stoping b axon
extrinsic MB
axon
b axon
WNT5
stop ?
LIO
RTK

27. Structural features of Ryk subfamily receptors

28. Cleavage and nuclear translocation of the Ryk intracellular domain (ICD)
mediates neurogenesis

29. Wnt/Ryk-mediated axon repulsion in the
developing versus injured adult spinal cord

30. Ephrins and their Eph receptors

31. Wnt/Ryk-mediated axon repulsion counterbalances ephrinB1/EphB-mediated
attraction in retinotopic mapping