Glia And Neurotransmittera Flashcards
What is the function of oligodendrocytes?
Insulation and myelination
What is the function of astrocytes?
Support
Provide lactate as energy by the glucose of lactate shuffle
Control of Neurotransmitters as glutamate is toxic
Buffer potassium
Form the blood brain barrier by podocyte feet
What is the function of microglia?
Phagocytosis to remove debris foreign material and recognise foreign material
Describes the blood brain barrier
It is a barrier between the blood and the brain
It has a basement membrane fenestrated capillaries and astrocyte feet
Tight junctions and endothelial cells lining the capillary
Describe the functions of the blood brain barrier
Support
Maintains correct environment
Oxygen, carbon dioxide, water can diffuse freely
Glucose, amino acids, potassium are transported across
Explain the immunity in the CNS
Mainly by microglia because oedema leads to increased intracranial pressure so microglia acts as antigen-presenting cells
T cells can enter the CNS but CNS inhibits pro inflammatory T-cell response
Give examples of amino acid neurotransmitters in the CNS
Glutamate
Glycine
GABA
Give examples of biogenic amines neurotransmitters in the CNS
ACh Noradrenaline Dopamine Histamine Serotonin
Give examples of peptides neurotransmitters in the CNS
Substance P
Somatostatin
Neuropeptide Y
Is glutamate excitatory or inhibitory?
Excitatory
70% of CNS synapses
Give examples of inhibitory neurotransmitter is and state where the act
GABA the main inhibition is in the brain
Glycine acts in the brainstem and spinal-cord
Name the glutamate inotropic receptors
AMPA - na/k
NMDA - na/k/ca
ketamine - na/k
How do the glutamate inotropic receptors work?
Binding leads to activation and depolarisation
NMDA you need glutamate to bind at the cell to be depolarised to allow ion flow through the channel and they’re blocked by magnesium at rest
What is there metabotropic glutamate receptor and how does it work?
MGluR1-7
GPCR
IP3 and calcium or
Inhibits adenyl cyclise which leads to decreased Camp
How do you GABA and glycine work?
They are integral chloride channels and opening leads to hyper polarisation and IPSP which reduces action potentials
What response does ethanol have to GABA?
Enhances response
Which drugs bind to GABAa receptors?
Benzodiazepines and barbiturates
Treat anxiety depression and epilepsy
Where is Ach found in the brain?
Basal forebrain and the brain stem
Diffuse projections to cortex and hippocampus
What is Ach function?
Memory
Arousal
Motor control
Which disease is associated with a decline in Ach?
Alzheimer’s
Treat with cholinesterase inhibitors
What are the dopamine pathways in the brain?
Mesocortical pathway
Mesolimbic pathway
–> mood, arousal and reward
Nigrostriatal pathway - motor control
What diseases are associated with dopamine?
Parkinsons (reduction)
Schizophrenia (increase)
What receptors are NA receptors?
Alpha and beta GPCRs
Where are NA receptors found?
Hypothalamus, Cortex, amygdala, cerebellum
Cell bodies are in brainstem
What is the function of NA in the brain?
Arousal and mood
What disease is associated with noradrenaline?
Depression - reduction
