1. Brain development

2. Timing

3. The beginning

4. Differentiation

5. Neural tube

6. Spinal chord and PNS

7. Spinal chord and PNS
Migration of cells from spinal chord to periphery (e.g., gut, heart, peripheral sensory organs.

8. Development of sensory & motor neurons
Alignment of sensory and motor neurons (motor & proprioception)
Proper Central Pattern Generators and reflexes require proper development of local circuits

9. Sense chemical gradients and orient axonal growth
Axonal growth cones
Sense chemical gradients and orient axonal growth

10. Setting up the connections
Where and when should the axon grow?
Decussation

11. Motor neurons to muscles
Setting up innervation

12. Competition among synapses
Synaptic pruning - PNS
Competition among synapses

13. Cells are programed to die unless they get NGF….
Nerve growth factor
Cells are programed to die unless they get NGF….

14. Cell death

15. Anterior segments Midbrain Mesencephalon Hindbrain
Signaling cascades govern
Cell differentiation & Migration
Diencephalon
Telencephalon

16. Cortical layers
Glial fibers

17. Eyes

18. Eyes to brain
Setting up topography…

19. Synaptic pruning - CNS

20. Occular dominance in a neonate monkey V1
Synaptic pruning - CNS
Occular dominance in a neonate monkey V1

21. Synaptic pruning is activity dependent
Hebbian learning

22. Synapses during development

23. Synaptic plasticity
Map space with inter-aural differences

24. Synaptic plasticity

25. This shift can only happen in young owls…
Synaptic plasticity
Axonal projections from the Inferior Coliculus to the visual tectum shift.
This shift can only happen in young owls…

26. A developmental period with enhanced plasticity.
Critical periods
A developmental period with enhanced plasticity.
Imprinting

27. Critical periods
Bird song development

28. Critical periods

29. Innervation of primary visual cortex
Critical periods
Innervation of primary visual cortex