Lecture XX - Neurogenesis

Neurogenesis

The process by which new neurons are formed in the brain.

Radial glia

Progenitor cells that guide the migration of neurons during development.

Multipotent

Referring to progenitor cells that can develop into multiple types of neurons and glia.

Inhibitory interneurons

Type of neuron that reduces brain activity, often GABAergic and important for balancing excitatory neurons.

Ganglionic eminence

A temporary structure in the developing brain that helps guide certain neurons to their final destinations.

Tangential migration

The sideways movement of neurons, often seen in some interneurons as they migrate from the ganglionic eminence.

Radial migration

The movement of neurons in a straight line along radial glial cells from inner brain areas to the outer layers of the cortex.

Oligodendrocytes

Glial cells responsible for creating the myelin sheath that insulates neurons and aids in faster electrical signaling.

Post-embryonic neurogenesis

The creation of new neurons after birth, particularly during childhood.

Adult neurogenesis

The process where new neurons are formed in the adult brain, primarily in the hippocampus.

Neural tube

The embryonic structure that develops into the brain and spinal cord.

Neural crest

Cells at the edges of the neural tube that migrate to form various structures throughout the body.

Epithelial-to-mesenchymal transition (EMT)

A process that allows neural crest cells to become migratory by losing their epithelial structure.

Ephrin

Signaling molecules that direct neural crest cell migration by repelling or attracting them to certain areas.

Cranial neural crest

Cells that migrate to form structures such as nerves, facial bones, and ganglia.

Trunk neural crest

Cells that follow specific migratory paths to become sympathetic ganglia, sensory ganglia, and more.

What are interneurons?

Interneurons are neurons that serve as intermediaries between sensory and motor neurons, facilitating communication within the central nervous system.

What is the role of excitatory interneurons?

Excitatory interneurons release neurotransmitters like glutamate to promote action potentials in adjacent neurons.

What is the role of inhibitory interneurons?

Inhibitory interneurons typically release GABA to reduce the activity of neurons, helping to maintain balance in neural circuits.

What are the two main types of neuronal migration?

The two main types of neuronal migration are radial migration (straight-line movement along radial glial cells) and tangential migration (sideways movement).

What guides radial migration?

Radial migration is guided by radial glial cells which provide scaffolding for neurons moving from inner brain areas to the cortex.

What distinguishes tangential migration from radial migration?

Tangential migration involves neurons moving sideways and is often utilized by interneurons migrating from the ganglionic eminence.

What is the significance of interneurons in the nervous system?

Interneurons play critical roles in modulating and integrating signals within neural circuits, influencing overall brain function.

Neural crest cell fates

Neural crest cells can differentiate into a variety of cell types, including neurons, glia, pigment cells, and structures in the face and heart.