Neuro pt 3 Flashcards
ascending projections that stabilize neuronal responses release what?
biogenic amine neurotransmitters
what causes depression
insufficient release of amine NTs
what do antidepressants do
block norepinephrine and serotonin uptake at the limbic system
what causes schizophrenia
excess release of biogenic amines
what type of drugs are used to treat schizophrenia
neuroleptics
block dopamine and serotonin receptors
what can cause excessive dopamine secretions
genetic predisposition or brain damage in a fetus
what is the function of the limbic systme
control behavioural and emotional responses
where is the hippocampus
temporal lobes
what is the hippocampus responsible for
memory formation, spatial memory and navigation
what is the function of the amygdala
controls and regulates emotions and emotional responses
what is alzhemiers disease
a progressive cortical atrophy
what are two physiological traits of alzheimers
neurofibrillary tangles and plaques
deficits in ACh levels due to a loss of ACh neurons
what is an amyloid plaque
aggregates of misfolded proteins formed in neurons
what are neurofibrillary tangles
abnormal accumulation of Tau protein
aggregates of misfolded proteins formed in neurons
amyloid plaque
abnormal accumulation of Tau protein
neurofibrillary tangles
what can be used to treat the symptoms of alzheimer’s disease
cholinesterase inhibitors - prevent degradation of synaptically released ACh
what is the most common movement neurodegenerative disorder
parkinsons
what is bradykinesia
slowness of movement
when the cortex sends excitatory signals to the striatum, what happens?
(in the direct pathway)
the striatum sends inhibitory signals to the GPI
the GPI sends LESS inhibitory signals to the thalamus
the thalamus gets excited, and sends MORE excitatory signals to the cortex
repeats
what does the direct pathway in the basal ganglia do
activates motor programs
when the cortex sends excitatory signals to the striatum, what happens?
(in the indirect pathway)
the striatum sends inhibitory signals to the GPE
The GPE sends LESS inhibitory signals to the sub-thalamic nucleus
The sub-thalamic nucleus gets more excited and sends MORE excitatory signals to the GPI
the GPI sends MORE inhibitory signals to the thalamus
the thalamus gets less activated, and sends LESS excitatory signals to the cortex
repeats
why does parkinsons occur
there is a loss of dopaminergic cells in the substantia nigra (the pars compacta) - cannot regulate the thalamus
what are Lewy bodies and lewy neurites
misfolded proteins
when would you find lewy bodies and neurites
in a patient with parkinsons
what part of the body does ALS affect
motor neurons
damage to upper motor neurons with ALS lead to waht
spastic paralysis
hyperflexia
damage to lower motor neurons with ALS lead to waht
flaccid paralysis
decreased muscle tone and reflexes
why does death occur with ALS
due to respiratory failure
what is huntingtons disease characterized by
involuntary movements
(chorea)
what is huntingtons caused by
expansion of a CAG tract in the coding region of the protein (a polyQ protein expansion)
what part of the basal ganglia does huntingtons most affect
the striatum
what causes is MS
progressive demyelination of neurons in the brain, spinal cord and cranial nerves
when does onset of MS occur
20-40 years of age
what is the hypothesis of the cause of MS
autoimmune origin
what are some symptoms of MS
blurred vision
weakness in legs
dysarthria
progressive weakness/paralysis in upper limbs
