Flashcards in Scenario 29 Deck (103)
What is the mean age of PD onset?
What are the risk factors for PD?
Family history, sex, age, family history, pesticide exposure
How many people does PD affect worldwide?
What are the motor symptoms of PD?
Shaking, stiffness, slowness and hypokinesia
Non motor symptoms of PD?
Fatigue, sleep deprivation, anxiety, depression, psychosis, dementia, constipation, pain
What is the role of dopamine in the brain?
Regulates cortical excitation of striatal neurons, stabilises the firing rate and excitability of striatal neurons and regulates their plasticity
Where does Parkinsons start in the brian?
Medulla and olfactory region- olfactory dysfunction in 70-100% of patients
What could differential diagnoses for PD like symptoms be?
Multiple system atrophy, progressive supranuclear palsy, drug induced, vascular, structural- toxins, infections, metabolic
Where is acetylcholine released?
From lower motor neurones- GI tract, preganglionic autonomic nerves, post ganglionica parasympathetic, retina
Nucleus basilis in brain to thalamus and cortex (not cerebellum)
How is acetylcholine synthesised?
Choline and acetyl CoA (synthesised in cell body and transported to terminals)
How is acetylcholine stored?
Vesicle in presynaptic terminal
How is ACh released?
Calcium dependent vesicular release at the end terminal
What ACh receptors are there?
Ligand gates ion channels (nicotinic) and GPCRs (muscarinic)- 2 subgroups M1,M3,M5 (Gq) and M2,M4 (Go)
How is Ach reuptaken?
Choline transporter (after its degraded)
How is Ach degraded?
To choline and acetic acid by acetylcholinesterase (in synaptic cleft)
What drugs interfere with Ach storage?
What drugs interfere with Ach release?
What drugs interfere with Ach nicotinic receptors?
Full agonists- Ach, suxamethonium, nicotine
Partial agonists- Verenacline
Reversible agonists- Pancronium and vercuronium
Irreversible agonists- alpfa-bungrotoxin
What drugs interfere with Ach muscarinic receptors?
Ach, muscarine, oxotremotine M
What drugs interfere with Ach reuptake?
What drugs interfere with Ach degradation?
What recreational drugs interfere with Ach?
Nicotine, scopolamine, herbane
What diseases are related to Ach?
Dementia, Myaesthenia gravis, PD, motion sickness, analgesia
Where is dopamine found?
Located in CNS-forebrain, striatum (PD), pineal gland via hypothalamus, hippocampus amygdala (not back of cortex or cerebellum)
How is dopamine synthesised?
Tyrosine from diet-->DOPA-->Dopamine
How is dopamine released
Calcium dependent vesicular release and end terminal adn along axon
What dopamine recptors are there?
D1 like- D1,5 couples to Gs (activates adenylate cyclase)
D2 like- D2,3,5 coupled to Gi (inhibits adenylate cyclase)
No ligand gating so no fast firing
How is dopamine reuptaken?
Diffuses round end terminal and taken up by DAT requiring Cl and 2Na
How is Dopamine degraded?
Via MAO/COMT/aldehyde dehydrogenase to homovalinic acid which can be measured in the blood/CSF/urine