Neurulation

1. Neurulation and Neural Crest Cells Neha Kaundal (10050) Sandeep Satapathy(10079) Smrithi Krishnan R(10090)

2. NEURULATION PRIMARY SECONDARY

3. How Secondary Neurulation?????

4. SPEMANN ORGANIZER CHANGE THE FATE OF CELL…!!!! INDUCES NEURAL PLATE FORMATION HOW…..?? SECRETE MOLECULES FOLLOW DEFAULT PATHWAY NEURAL FATE

5. Molecular Signaling of Primary Neurulation Positional confirmation for spatial differentiation

6. NEURULATION BEGINS HERE...!!! Shh Signaling from the Notochord reaches the MHP of the neuroepithelium

7. BMP4/BMP7 Neural Boundary Cells MHP Somites Chondrin , noggin, Follistatin FGF |---------------------| Fated Neural Crest Cells Neural Crest Cells E-cadherin N-cadherin N-CAM Hyaluron

8. Zippering action -Closure of Neural Tube Completes in 25days post embryonic development Completes in 27 days post embryonic development Apical constriction by rearrangement of actin, tubulin effect of BMP4/7 signaling Basal bulging out caused by movement of nucleus into this space signaled by shh from notochord

9. Cell Fates-Neural tube cells/Neural crest cells

10. SENSORY NEURONS MOTOR NEURONS FORMATION OF HEAD,TRUNK &TAIL

11. 24-hr Chick 22-23 days of Human

12. DEFECTS…….. ANENCEPHALY SPINA BIFIDA END OF NEURROSTRAL AL TUBE FAILS TO CLOSE MISEPRESSION OF WRONG CADHERIN LEADS TO FAIL TO SEPARATE EPIDERMAL ECTODERM AND NEURAL LAYER

13. EXPERIMENTAL APPROACHES

14. Unfortunately, simplicity is not the answer. In actuality, the folding of the neural tube is still not entirely understood. The simplistic model of the closure occurring in one step cranially and caudally does not explain the high frequency of neural tube defects. Proposed theories include that closure of the neural tube occurs in regions, rather than entirely linearly

15. Thank You