Facts about developing brain

1. Many neurons die during fetal life

Brain development starts with overproduction of neurons. Many neurons die during brain development to ensure proper connection between neurons and well-formed functional neuronal networks. There is regulation in number of synapses formed between neurons a process called synaptic pruning ensuring precise connections. Example Eyes (retina) are connected to visual areas of the brain (visual cortex, back of our head)

2. Human brain reaches 90% of its adult volume by the age of 6 years

Human brain develops from neural tube formed from neuroectoderm. Brain development begins around 9^th week of life, continues through whole pregnancy (gestation). Human brain develops most during early years of life. Reaching 70 % of adult volume by the age of 1 year, 80 % by the age of 2 years and 90 % by the age of 6 years. Maturation of brain tissue continues till adolescence or young adult age of 25 years especially the rational part of brain. Some scientist argue that the brain continues to grow throughout the life time.

3. GABA is excitatory neurotransmitter in developing immature neurons

GABA (gamma γ amino butyric acid) an inhibitor neurotransmitter in adult brain is excitatory in developing neurons. GABA acts via its GABA A receptor, a ligand gated chloride channel. Normally the extracellular concentration of chloride ions (Cl^-) is more in adult neurons