Lecture 4 - Different classes of Glia and their properties Flashcards
List the three types of cells in the brain?
- Neurones
- Blood vessel cells
- Glia
List the types of glial cells?
- Radial glia (CNS)
- Ependymal cells (CNS)
- Oligodendrocytes (CNS)
- Schwan cells (PNS)
- Microglia (CNS)
- Satellite cells (PNS)
- Astrocytes (CNS)
Where are ependymal cells found?
Exists within the lining of the ventricular system (only place)
What do Oligodendrocytes do?
They myelinates axons in the CNS, so the axon potential is faster.
What do Schwann cells do?
Myelinate axons in the peripheral nervous system
What are Micoglia important for?
they are like the phagocytes of the nervous system?
What are satellite cells?
They are like astrocytes and exist in the PNS
What do Astrocytes do?
- An astrocyte contacts synapses
- regulate blood pressure.
- They have metabolic functions and trophic functions.
- take up a lot of glutamate to metabolise to glutamine and this is then sent back to neurones
- Astrocytes can scavenge potassium
- Homeostasis of interstitial fluid
what is released form astrocytes?
glio transmitter is a transmitter released form astrocytes. They are the same as neurotransmitters.
What is the tripartite synapse?
Made of post- and pre-synaptic membranes as well as astrocytes
What is the fluid in the brain?
- Brain has four fluid compartments
- 10% of the volume is cerebral spinal fluid
- 10% is blood
- 80% is brain : brain cells and interstitial spaces
How do astrocytes feed neurones?
-Astrocytes presumably feed neurones with lactate they produce from glucose, neurones do not use glucose to produce ATP they use lactate.
Which astrocytes reside in the white and grey matter?
- Fibrous astrocytes reside in the white matter
- Protoplasmic astrocytes reside in the grey matter
What experiment was done involving staining of astrocytes?
-Experiment was done where human astrocytes were injected into a mouse, the human astrocytes then took over.
What is astrogliosis?
Astrogliosis: if someone is slashed across the brain astrocytes go to this damaged area. This is bad because axons can not go through the area where there’s a lot of astrocytes. This is counter productive. The frog brain does not do this.
What is the blood brain barrier?
Blood brain barrier: made by astrocytes which are close together in the brain, nothing will go through.
when transformed what do ependymal cells make?
When transformed they make choroid plexus together with blood vessels.
what stem specialised radial glia in the cerebellum called?
Bergman Glia
whats the main role of radial glia?
help neurones travel to there destination
are neurones made where they resign?
no
what part of the radial glia is used as a navigator?
Elongated parts
Different classes of cells all derivative from ____ _____ cells.
radial glial
what do radial glia cells give rise too?
neurones and astrocytes and other glial cells
are neurones born before or after astrocytes?
before
How many axons can a oligodendrocyte rap around?
many different axons
One _____ is myelinated by many different ______.
- axon
2. oligodendrocytes
Schwann cells have _______ activities?
- Phagocytic
Schwann cells are a type of?
microglia
one Schwann cell can wrap around how many axons?
one
If an axon is created in the cns but moves to the pns, it is myelinated by what?
myelinated by both Schwann and oligodendrocytes
what do astrocytes supply to neruons?
lactate, glutamate, interstitial fluid
what are the two general forms of plasticity in regards to astrocytes?
Hebbian and homeostatic
do astrocytes have the same receptors as neurones ?
yes
fluid in the brain is….
Fluid is taken up by the lymphatic system
The brain in place for the lymphatic system has a glymphatic system
do neurone store glucose?
no
Do astrocytes divide?
yes
