Developmental Neurogenesis and Brain Development

Neurons

Cells in the human brain that number around 86 billion.

Glial cells

Cells in the human brain that are at least twice as numerous as neurons.

Neurons

Cells in the human brain that number around 86 billion.

Glial cells

Cells in the human brain that are at least twice as numerous as neurons.

Synapses

Connections between neurons that exceed 100 trillion in the human brain.

Developmental Neurogenesis

The process of neuron formation, specialization, and connection across synapses during development.

Zygote

A cell from fertilization to 4 days old that can form any cell type in the adult organism.

Blastula/Blastocyst

A hollow ball of cells around 4-5 days old that is still totipotent.

Gastrula

A 3-layered ball of cells that forms around 7-10 days old, with cells from one layer forming specific cell types.

Ectoderm

The outer layer of cells that forms skin and the nervous system.

Mesoderm

The middle layer of cells that forms muscle, blood, and bone.

Endoderm

The inner layer of cells that forms internal organs like lungs and liver.

Neural Plate

Part of the back ectoderm forming the neural tube and neural crest by folding.

Neural Tube

A hollow tube forming the spinal cord and brain through vesiculation.

Neural Crest

Cells migrating out to form peripheral nerves.

Cell Proliferation

Formation of two new cells from one by a neural stem cell.

Stem Cell

An unspecialized cell dividing to form two other stem cells.

Neural Stem Cell Proliferation

Starts shortly after conception and completes 4-5 months post-conception, forming over 100 billion neuronal precursor cells.

Primitive Neuroectodermal Tumors

Rare tumors in children due to abnormal neural stem cell proliferation.

Microcephaly

Abnormally small brain due to stem cell death or insufficient proliferation.

Cell Migration

Movement of cells from one place to another.

Tangential Migration

Moving up/down or around.

Radial Migration

Moving out from the center.

Chemical Differentiation

Activation of master regulatory genes by chemical signals to produce neuron-specific proteins.

Morphological Differentiation

Cell taking on its adult form with dendrites & axons forming.

Synaptogenesis

Formation of a functional synapse between neurons.

Neuronal Cell Death

Programmed cell death triggered in defective or unnecessary cells.

Neurotrophins

Chemicals inhibiting cell suicide and promoting neuronal growth and survival.

Synaptic Pruning

Elimination of excess neurons and synapses.

Myelination

Formation of myelin sheaths around neurons.

Leukodystrophies

Conditions resulting from defects in myelination.

Grasping Motor Behaviors

Motor behaviors like palmar grasp, mature grasp, and fine pincer grasp in infants.

Pruning

Elimination of less effective motor neurons and synapses

Language Acquisition

Rapid increase in vocabulary influenced by childhood environment

SES Disparity in Language

Higher SES children acquire more words due to environmental factors

Cortical Thickness Increase

Thickening of speech areas for the language heard and spoken

Bilingual Advantage

Retention of more speech synapses in bilingual individuals

Neurogenesis

Formation of new neurons in the hippocampus

Enriched Environment Benefits

Improved cognitive abilities and brain structure from stimulating surroundings

Exercise and Neurogenesis

Increased hippocampal neuron formation from physical activity

Place Neurons

Neurons in the hippocampus that fire in response to a particular view or orientation

Synaptic Transmission

Neurons communicate by releasing neurotransmitters across the synapse, binding to receptors on the postsynaptic neuron

Synaptic Plasticity

Change in synaptic strength, resulting in a smaller or larger postsynaptic potential

Short Term Memory

Involves changes in existing synaptic proteins, leading to short-term changes in synaptic strength

Long Term Memory

Involves gene expression changes for longer-lasting synaptic strength changes or formation of new synaptic connections

Habituation

Temporary decrease in synaptic responsiveness to repeated stimuli, allowing avoidance of non-harmful or unimportant stimuli

Long Term Potentiation (LTP)

Long-lasting increase in synaptic transmission due to repeated activation, requiring new gene expression

Amnesia

Loss of memory, which can be retrograde (loss of pre-existing memories) or anterograde (inability to form new memories)

Apoptosis

Programmed cell death requiring signaling and gene expression, leading to cell shrinkage and fragmentation

Necrosis

Accidental cell death not requiring signaling or gene expression, leading to cell swelling, lysis, and inflammation