Life-Span Development of the Brain and Behavior Flashcards

A comprehensive vocabulary flashcard set covering the six stages of neural development, guidance molecules, degeneration types, neurotrophic factors, and developmental visual plasticity based on Chapter 7.

Neurogenesis

The mitotic production of neurons from nonneuronal (precursor) cells, representing the first stage of neural development.

Cell migration

The movement of cells to establish distinct populations within the developing nervous system.

Differentiation

The transformation of precursor cells into distinctive neurons or glial cells via specific gene expression.

Synaptogenesis

The establishment of synaptic connections during brain development through extensive growth of axons and dendrites.

Neuronal cell death

The selective, programmed cell death (apoptosis) of many nerve cells during development.

Synapse rearrangement

The loss or development of synapses to refine synaptic connections throughout life and development.

Ventricular zone

The innermost layer of the developing neural tube where precursor cells divide by mitosis.

Radial glial cells

Glial spokes that guide migrating neurons from the ventricular zone outward to their destination in the cortex.

Cell adhesion molecules (CAMs)

Molecules laid down along migration paths that guide migrating cells and growing axons via cell-cell interaction.

Growth cone

The tip of a growing axon or dendrite that extends filopodia to sense chemical guidance cues.

Filopodia

Fingerlike extensions of growth cones that adhere to CAMs and contract to pull the growth cone forward.

Chemoattractant

A chemical signal that attracts growth cones toward a specific developmental target.

Chemorepellent

A chemical signal that repels or steers growth cones away from specific areas, such as driving axons away from the midline.

Myelination

The wrapping of axons by glial cells (such as Schwann cells in the PNS) to boost the speed of neural communication.

Apoptosis

Programmed cell death, a normal developmental process triggered by death gene expression.

Caspases

Compounds produced by expressed death genes during apoptosis that degrade cellular proteins and DNA.

Neurotrophic factor

A target-derived substance (such as NGF or BDNF) that feeds innervating neurons to promote their survival.

Nerve growth factor (NGF)

A specific neurotrophic factor that prevents neuronal apoptosis when taken up by innervating axons.

Brain-derived neurotrophic factor (BDNF)

A neurotrophic factor produced by target cells that regulates gene expression in innervating soma to keep the neuron alive.

Retrograde degeneration

Neuronal degeneration occurring close to the cell body, which often causes the entire cell to degenerate.

Anterograde degeneration

Degeneration occurring far from the cell body where, in the PNS, the axon can sometimes sprout and regrow.

Transneuronal degeneration

Neuronal degeneration that spreads to connected neurons, causing downstream atrophy.

Chemoaffinity hypothesis

The hypothesis stating that each cell has a unique chemical identity guiding axon regrowth to reestablish original connection patterns.

Sensitive period

A developmental window during which specific experience or treatment causes permanent changes to neural circuitry.

Ocular dominance

The degree to which a neuron in the visual cortex responds to input from one eye versus the other.