Lecture Content Flashcards
What is the layout of a multipolar neuron?
1 axon, multiple dendrites.
What is the layout of a bipolar neuron?
1 axon, 1 dendrite which then branches.
What is the layout of a pseudo-unipolar neuron?
1 process (containing cell body) which immediately branches.
What is the layout of a unipolar neuron?
Dendrites extend from the axon.
- What do anterograde microtubules transport?
2. What direction and speed can this transport occur?
- NTs, structural elements, metabolic components
- Cell body to axon via kinesins.
FAST (1-4cm/day).
SLOW movement (0.05-1cm/day) can also occur.
- What do reterograde microtubules transport?
2. What speed and direction can this transport occur?
- Aging mitochondira and vesicles. Signals indicating damage and repair requirement.
- Axon to cell body via dynesins.
FAST (5-25cm/day)
What does DTI stand for, and what can it show?
Diffusion Tensor Tractography. Type of MRI showing neuronal pathways through the brain- outlining connectivity pathways.
How many different neuronal inputs CONVERGE onto one neuronal cell body?
10,000
How many outputs are there from any neuron?
100s
Which neuroglial cells promote axon regeneration?
Schwann cells
How many axons can one oligodendrocyte myelinate?
40-50
What type of cell regulates glutamate levels in the synapse via its glutamate transporter activity?
Astrocytes
Which cell type forms the Glial Scar after injury?
Astrocytes
How do astrocytes regulate the BBB?
Via formation of the glial limitans
Which ion concentrations do astrocytes regulate?
K+, H+, H20
What types of astrocytes exist, and what is their structure, location and function?
- Fibrous
Long and stretched;
Grey matter;
Homeostatic role - Protoplasmic
Star Shaped;
White matter;
Provide axon stability and support
What two states can microglia exist in?
- Multiple processes extending (with ATP receptors)
2. Rounded (phagocytic)
What is the most abundant form of ependymal cell and what is its function?
Ependymocytes. Form an epithelial lining, containing cilia on their apical surface for CSF circulation, and microvilli for CSF absorption
Where are tancytes found, and what is their function?
IIIrd ventricle. Act as sensors for molecules/secreted hormones within CSF
What is the function of choroid plexus cells? What type of neuroglial cell are they?
CSF production and secretion in all brain ventricles.
Ependymal cells
How to Schwann cells promote axon regeneration?
- Upregulate laminin and neurotrophin (permissive to axon regeneration)
- Rapidly phagocytose myelin debris.
What is the role of a satellite cell, and where are they found?
Provide structural and metabolic support to neurons. Foudn within the DRG and sympathetic ganglia.
What are the 5 ways of interfering with neuronal transmission?
Synthesis Storage Release Receptor Removal
How is L-Dopa used, and in which disease?
L-dopa is used to treat Parkinson’s disease. It promotes dopamine synthesis and release in remaining healthy dopaminergic neurons.
