NEURODEVELOPMENT TIMELINE

• Stages: Conception → Birth → Age (years)
• Key Processes: Proliferation & neurogenesis, Cell migration, Neurite outgrowth, Synaptogenesis, Neural network formation (3rd trimester), Postnatal development.

EARLY EMBRYONIC STAGES (Conception - 2 Weeks)

• Stages: Fertilization, Blastulation (formation of blastula), Gastrulation (ectoderm, endoderm formation).

NEURULATION AND NEURAL TUBE (2 – 4 Weeks)

• Central nervous system (CNS) forms neural tube; Neural crest forms peripheral nervous system (PNS), enteric nervous system (ENS), and other structures.

VESICLE DEVELOPMENT (4-8 Weeks)

• Primary brain vesicles: Prosencephalon (forebrain), Mesencephalon (midbrain), Rhombencephalon (hindbrain).
• Secondary brain vesicles: Telencephalon, Diencephalon, Metencephalon, Myelencephalon.

SPINAL CORD DEVELOPMENT (4-8 Weeks)

• Grey matter (neuron cell bodies) and white matter (axons).

SOMITE DEVELOPMENT (4-8 Weeks)

• Somites differentiate into dermatome (skin), myotome (muscle), sclerotome (vertebrae).

ACTIVE VS PASSIVE LEARNING

• Passive: Absorb and memorize; one-way communication.
• Active: Inquiry & creation; engagement in learning through discussion and reflection.

NEURAL TUBE DEFECTS (NTD)

• Anencephaly: Absence of brain/skull; linked to folic acid deficiency (0.1% occurrence).
• Spina bifida: Failure of caudal neural tube closure (0.1% occurrence).

FETAL STAGE DEVELOPMENT (Week 8-9 Months)

• Continued development of brain vesicles: Telencephalon and others.
• Neuronal migration: Inside-out development of cortical layers.

TIMOTHY SYNDROME DISORDER

• Rare genetic neurodevelopmental disorder caused by mutation in CACNA1C gene; features QT-prolongation, syndactyly, and autism spectrum disorders.

NEURONAL MIGRATION DEFECTS (Week 8 - 9 Months)

• Conditions: Lissencephaly (smooth brain), Pachygyria (thick folds).