Brain Development from Conception to Birth

First Four Weeks

• Neural Plate Formation
  • Forms in the outermost layer of embryonic cells.
• Neural Tube Formation
  • Neural plate folds into the neural groove.
  • Neural groove curls to form the neural tube.
• Differentiation of Neural Tube
  • Forebrain: Develops into the cerebral cortex.
  • Midbrain: Becomes a neural relay station.
  • Hindbrain: Controls basic physiological processes (e.g., breathing, heart rate).
  • Spinal Cord: Pathway for information between brain and body.

Weeks 4 to 8

• Rapid growth of the embryo.
• Facial development becomes human-like.
• Eyes migrate forward.
• Emergence of two distinct hemispheres of the cerebral cortex.

Weeks 8 to 26 (Fetal Stage)

• Growth of the cerebral cortex to cover the midbrain.

Week 28 to Birth

• Cortex Expansion
  • Cortex expands in surface area, becomes wrinkled and folded (gyri and sulci).
  • Facilitates creation of a vast neural network.
• Neurogenesis
  • Formation of new nerve cells.
  • Nerve cells migrate outward, guided by glial cells.
  • Brain grows in layers, similar to onion skins.
  • Nerve cells acquire specific characteristics.

Neural Communication Developments

• Dendrites and Axons
  • Dendrites receive incoming signals.
  • Axons carry outgoing signals.
• Synaptogenesis
  • Proliferation of synapses in the brain.
  • Synapses are points of communication between neurons.
  • Synaptic growth called exuberant synaptogenesis continues into the first year of life.

Synaptic Transmission

• Impulse crosses synaptic gap appearing as a green ball of light.
• Neurotransmitters (red balls of light) released at axon terminals.
• Neurotransmitters facilitate communication between neurons across synapses.

Synaptic Pruning

• Occurs during fetal period, infancy, childhood, and adolescence.
• Pruning customizes the brain's nervous system in response to individual experiences.