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Cell Biology of Neurons and Glia
Competencies:
- Describe the basic cellular components of neurons and glia of the central nervous system.
- Identify how those components differ in the peripheral nervous system.
- Define the physiological and functional interactions between cellular constituents in the central nervous system.
- Outline the basic cellular mechanisms underlying brain function.
- Describe integration of cellular constituents in brain plasticity, repair and high function.
To master
the material presented in this lecture:
Read ...
Purves text, pp 4-7 Chapter 7
Look at the Review Questions below ...
Listen
to the lecture and focus on the following points ...
- Remember to integrate with Neurophysiology, Tissue Biology and Gross Anatomy!
- Clusters of neurons in CNS are called nuclei.
- Layers of neurons are generally called cortex.
- Neuronal soma and dendrites receive 100’s to 1000’s of synapses.
- One axon carries action potentials away from the soma of the cell.
- Slow axonal transport, 1 to 4 mm/day, rate of replacement and repair.
- Fast axonal transport, 400 mm/day.
- Microtubules, kinesin, dynein.
- Long term potentiation may be a basis for memory.
- Glia represent about 90% of the cells in CNS.
- Glia are not post-mitotic.
- Astrocytes, oligodendrocytes and microglia in CNS and Schwann cells in PNS.
- Glia influence transmitter metabolism, ionic balance, and insertion pts of ion channels, as well as trophic substances, rate of axonal conduction and development.
Consider the Following Questions
...
- What advantages does myelin impart to neuronal function?
- What is the rate of repair you might expect for a severed nerve in the periphery?
- Explain ways in which astrocytes influence synaptic function.
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