Lecture 8 week 4 Flashcards
What are major cell types of the adult human central nervous system
- Neurons
- Oligodendrocytes (CNS) &
Schwann cells (PNS) - Astrocytes
- Microglia
- Ependymal cells
What is Multiple Sclerosis
- Destruction of myelin sheath
due to an autoimmune disorder - Unmyelinated axon – 0.5 to
2m/s - Myelinated axon – 6 to 120m/s
How do neurons target cells?
With a specific neurotransmitter
Where do neurons typically release one type of neurotransmitter?
At a given pre-synaptic neuron (ex. dopamine, seratonin, norepinephrine, acetylcholine, etc.)
What can inputs be?
Either excitatory or inhibitory
What is net response based on?
Based on overall effect of all inputs
What to neurons have the ability to do?
Diverge, converge and form networks.
What is synaptic divergence?
Many other nerve cells influenced by one
What is synaptic convergence?
One nerve cell influenced by many others
What happens around 10 years of age in humans, regarding the brain
Lots of remodelling is done within brain’s neural network. Brain develops new synapses and prunes away unused synapses.
What are some changes in teen/emerging adult brain?
- Growth in size 90% complete but massive reorganization & development of synapses i.e. networking
- Increased sensitivity to dopamine – does this explain why teens respond strongly to social reward?
- Large increase in myelination i.e. increase in transmission speed of neurons
- These changes should facilitate learning & social networking which are important for survival – does it also explain risky behaviour?
What do oligodendrocytes and shwann cells do?
Produce myelin
Where do oligodendrocytes span?
Oligodendrocytes span multiple axons and are found in the CNS
Where do shwann cells span?
Shwann cells do not span multiple axons and are found in the PNS
