PD & ALS Flashcards
(32 cards)
What are the characteristics of LMN disorders?
Atrophy, twitches, loss of muscle tone and less active tendon reflexes
What are the characteristics of UMN disorders?
Spasticity, overactive tendon reflexes
What causes myasthenia gravis? (MG) What are the effects?
Cause when antibodies block, alter, or destroy the nACh receptors at the neuromuscular junction. Decreasing effects in the muscle
What causes LEMS? What are the effects?
Ca2+ voltage channels are blocked on pre-synaptic neuron. EPPS are decreased
What happens in ALS?
Both the UMN and the LMN degenerate or die and stop innervating muscles.
What is the pathology of ALS?
As LMNs begin to die –> sprouting of other LMNs and aberrant activity (causes fasciculations & twitches)
What do you see in the cellular pathology of ALS patients?
Stress granules found in the cytoplasmic inclusion bodies of UMN. The granules contain TDP-43 aggregates and often become a target for ubiquitination. If a patient has SOD1 mutations then see aggregated SOD1 in stress granules.
What do aggregated proteins do?
The soluble alpha helix becomes an insoluble beta sheet and a change in 3D structure causes problems for functioning
What are the genes that cause an increased risk for ALS if mutated?
SOD1, FUS, TDP-43, C9orf72
What is cell autonomous?
A genetic trait in multicellular organisms in which only the genotypical mutant cells exhibit the mutant phenotype
What is cell non-autonomous?
A trait in which genotypical mutant cells can cause other cells to exhibit a mutant phenotype
What is the dying forward theory of ALS?
UMN –> LMN. Maybe glutamate excitotoxcity activates apoptosis via NMDA
What is the dying back theory of ALS?
Starts in muscles with loss of trophic factors
What does Riluzole do?
Inhibits Na+ channels, limits glu release
Label the parts of the Basal Ganglia
What is transient vs. tonic?
Transient: cell at rest doesn’t release anything
Tonic: At rest, cell dribbles a little bit out
What happens when A is at rest in this disinhibitory circuit?
What happens when A is excited in this disinhibitory circuit?
What is the direct pathway of the basal ganglia?
Direct –> striatum (+), MSN (-), GPi (-), Thalamus (+)
What are the enzymes required to synthesize DA?
Tyrosine hydroxylase and DOPA decarboxylase
What kind of receptors do MSNs in the direct pathway have? What is the effect?
MSNs that project to GPi have D1 receptors with a Gs protein that activated adenylate cyclase
What kind of receptors do MSNs in the indirect pathway have? What is the effect?
MSNs that project to GPe have D2 receptors with a Gi protein that inhibits adenylate cyclase
What are the symptoms of Parkinson’s disease?
Motor: tremor at rest, slowness of movement, stiffness & rigidity
Non-motor: Change in executive function, apathy, depression, dementia
What is the pathology of PD?
Loss of DA neurons in substantia nigra & over-expression of the alpha-synuclein protein leads to beta sheet confirmation and aggregates called Lewy bodies
