L20: Neurogenesis and Nervous System Development

Neurogenesis

Process of neuron formation and development.

Ventricular zone

Region where neural stem cells produce neurons.

Lateral inhibition

Cell interaction mechanism regulating neuron production.

Delta signaling

Communication that represses neurogenin expression.

Neurogenin

Transcription factor promoting neuron differentiation.

Radial glial cells

Guiding cells for neuron migration.

Cerebral cortex layers

Six distinct neuron layers formed by migration.

Growth cone

Leading tip of axon outgrowth.

Axon outgrowth

Extension of axons towards target cells.

Synapse formation

Creation of connections between neurons.

Synapse refinement

Process of optimizing synaptic connections.

Ephrins

Molecules guiding neuron positioning through attraction/repulsion.

Eph receptors

Bind ephrins to mediate cellular signaling.

Commissural neurons

Neurons crossing the midline of the nervous system.

Netrin-1

Gene essential for commissural neuron guidance.

DCC receptor

Netrin receptor mediating axon attraction.

Robo receptors

Inhibit or promote midline crossing in neurons.

Myelin sheath

Insulating layer around motor neuron axons.

Acetylcholine (ACh)

Neurotransmitter for nerve-muscle communication.

Neuromuscular junction

Synapse between motor neuron and muscle fiber.

Agrin

Proteoglycan that organizes ACh receptors.

MuSK

Receptor that stabilizes post-synaptic surface.

Neuregulin-1

Growth factor required for synapse maintenance.

Interneuron synapse formation

Similar mechanisms to neuromuscular junction formation.

Neuroligins

Cell adhesion molecules aiding synapse formation.

Cadherins

Adhesion molecules involved in synaptic connections.

Apoptosis

Programmed cell death ensuring neuron-muscle specificity.

Motor neuron survival

Requires contact with muscle for viability.

Pre-patterning

Initial arrangement of ACh receptors in muscle.

Chick motor neurons

Model for studying motor neuron development.

Floor plate

Structure guiding commissural neuron midline crossing.

Eph4A

Receptor mediating repulsive signals in neuron guidance.

Slit signaling

Inhibits axon crossing at the midline.

Robo3

Facilitates crossing and prevents recrossing.

Cerebral cortex

Brain region with layered neuronal structure.

Neuronal layers

Different shapes and functions in cerebral cortex.

Wnts

Signaling molecules involved in synapse formation.