Brain Development and Neurons Quiz

Development of the Brain and Neurons

• The brain has around 100 billion neurons, which make up 40-50% of the brain and have diverse shapes, sizes, and neurotransmitters.
• Neuronal proliferation occurs mostly in the first 5 months, while neuronal differentiation occurs mostly in 4-9 months. Neuronal connections continue to form postnatally.
• Glial cells, derived from neuronal crest cells, have various functions such as homeostasis, structural support, myelination of axons, and response to injury.
• The trilaminar embryo has three germ layers, and neural plate buckles down to form a groove, which forms the neural tube and neural crest cells that form the PNS.
• Failure of rostral neural tube closure results in anencephaly, while failure of caudal neural tube closure results in spina bifida.
• The brainstem has a diamond-shaped cavity with a sulcus limitans dividing it into dorsal sensory and ventral motor regions, and cranial nerve ganglia are associated with sensory function.
• The telencephalon forms the corpus callosum, basal ganglia, thalamus, and hypothalamus, while the lamina terminalis is the rostral tip of the neural tube.
• Sulci and gyri form as more cells form, and the insula cortex is overgrown by the temporal, parietal, and frontal lobes.
• Electrically active neurons allow rapid and reliable long-distance communication, and myelination occurs mostly postnatally.
• Astrocytes contribute to the blood-brain barrier and reuptake of neurotransmitters, while microglia are the resident immune cells of the CNS.
• The mesencephalon has colliculi, and the pons connects the brainstem to the cerebellum.
• The ventricles are remnants of the neural tube, and the cerebellar cortex, amygdala, and dorsal thalamus are parts of the prosencephalon.