how many different cell subtypes have been found in brain samples?
roughly 100
what are 9 major subtypes of neurons?
- von economo neurons
- radial neurons
- pyramidal neurons
- fork neurons
- place cells
- interneurons
can microglia replicate?
- they can but they do so at an extremely slow rate
what are sennessent cells?
cells that are no longer dividing
what are dystrophic cells?
- cells with structural atrophy
what are the 4 stages of microglia cells
stage 1: cells are ramified, surveillant, resting and homeostatic
stage 2: cells are activated and reactive
stage 3: cells are senessent
stage 4: cells are dystrophic
what is the difference between microglia in white matter and in grey matter?
- microglia in white matter often have a very flattened appearance. This is so they can track more easily up and down the white matter fibres
- (unstimulated) in grey matter have extended processes with many branches projecting in all directions.
- The cell bodies do not tend to move as much from their territories, instead the processes extend and retract to difference places to detect relavent signals.
why are CNS tumors relatively rare compared to tumors elsewhere in the body?
- the cancerous genes are normally genes associated with replication and brain cells are largely post mitotic
what is apoptosis and why is it good?
- the orderly mechanism of cell death in stressed or dying neuronal cells
- the orderly manner of it limits damage to bystander cells
what is necrosis and why is it bad?
- necrosis is a drastic and uncontrolled form of cell death
- this creates much larger regions of damage to surrounding cells
what is arborisation?
the degree of branching of the dendrites of the neurons
what protrudes across the length of the dendrite
- a series of spines
- these can be removed and reformed as needed
what part of the dendrites form synapses?
- the spines of the dendrites form synapses
what does the microtubule transport system provide for the cell?
- the rigidity, force and structure for molecules to travel across the cell
how are the nuclei in neurons different to other cells?
- neurons tend to have a very large nuclei with a prominent nucleolus
- this reflects their very high level of gene expression compared to other cells
- perhaps this is related to their high level of protein turnover and shifting in activity
what is the differences in neurons in terms of where translation occurs
- in most cells translation occurs in the cytoplasm
- in neuronal cells this can occur in other places
- for example some mRNA molecules are transported along the microtubules to the dendrites for translation to occur in the dendrites
- This can offer greater control over which proteins are made and where
- it can also control how long each mRNA is available for translation and can affect how much protein is made from the templates
what are the functions and structure of sensory neurons?
- conduct somatosensory information from the body to the spinal chord or brain
- they have a relatively simple structure compared to other neurons
what are the functions and structure of interneurons?
- connect sensory and motor activity of the CNS
- they connect to other interneurons, sensory neurons and motor neurons
- They have variable shapes such as pyramidal and purkinje
- They are the most common form of neuron
what are 3 things that can be used to classify neuron subtypes?
- morphology
- whole genome expression
- electrical activity
what is the function of motor neurons and where are they located?
they carry information from the brain and spinal chord to the muscles
they are located in the lower brain stem and the spinal chord
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topic 1 (brain cells and types)29
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topic 1 (brain cells SUBCELLTYPES)20
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topic 1 video 3 (communication between cells)3
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READING54
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Topic 2 electrical signals40
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Topic 3 (chemical synapses)32
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Topic 4 (neurotransmitters and receptors)72
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topic 5 (neurotransmitters in health and disease)31
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topic 6 (neuroactive drugs)45
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topic 746
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topic 8 neuroplasticity24
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topic 917
