Topic 2 - neurometabolic cascade Flashcards
where are Na and K most concentrated in a normal cell
K supposed to be in
Na supposed to be out
what happens to K during neuron damage
leaks out of the neurons
what is the effect of K leaking out of the neuron
increases resting membrane potential= easier activation
increase in fuel need = increased demand for glucose
what is the effect of Ca2+ leaks out of the damaged neurons
promotes vasoconstriction and cerebrovasculature
Ca2+ used in cell signalling and smooth muscle channels = increased muscle activation
what do the leak in K and Ca2+ overall cause
decreased efficiency in brain function because neurons aren’t being optimally reset
- recognised as clinical symptoms
what does the ionic influx of K cause
indiscriminate release of glutamate (powerful excitatory NT) from the massive activation
what is the problem with excess glutamate being released
- increased risk of seizures
- can trigger the voltage and ligand gated channels in the brain to depolarise and disrupt normal responses
what does the brain do to try and restore ionic homeostasis
(only happens where the neurons are damaged)
- depletion of intracellular energy reserves and Ca2+ levels
- causes decreased metabolism and potential challenges to neurovascular coupling
which elevated markers are related to neuroinflammation following concussion
inflammatory cytokines
- interleukin (IL)
- tumour necrosis factor (TNF)
(can also be released from other injuries - not brain specific)
what symptoms does ionic flux cause
migraine headache, light sensitivity, sound sensitivity
what symptoms does an energy crisis in the brain cause
vulnerability to second injury
what symptoms to axonal injury and impaired neurotransmission cause
impaired cognition
slowed processing
slowed reaction time
what symptoms do protease activation, altered cytoskeletal proteins, and cell death cause
chronic atrophy
development of persistent symptoms
