Acetylcholine Flashcards
General Info
Acetylcholine
• Cholinergic Neurons
• First neurotransmitter discovered
• Abundant in brain and periphery (more abundant than others)
• Abundant at neuromuscular junctions. Important for muscular contraction (Ach tells muscles to contract)
• Ach binds to receptors on motor end plate, causes contraction
• Paralysis occurs when Ach is blocked
Alzheimer’s:
- Loss of cholinergic neurons in basal forebrain results in Alzheimer’s
- Ach important for learning, memory, attention
Acetylcholine in Brain Stem:
In pons and midbrain
• Involved in sleep/arousal
Botulinum Toxin:
- Ach antagonist
- Anaerobic bacteria (thrives in oxygen free environment)
- Very deadly
- Prevents docking by breaking up snare proteins
- Results in paralysis of muscles, organs, causes death if it occurs in respiratory systems
Blepharospasm:
- Can’t open eyes because eye muscles are hyperactive
* Use botox to treat
Black Widow Spider Venom:
- Stimulates release of Ach
- Several bites needed to kill a healthy adult
- Causes muscle spasms
Receptors:
• Muscarinic receptor
o Metabotropic
• Nicotinic receptor
o Ionotropic
o Excitatory effect (Allow Na to enter cell)Atropine
Extract of belladonna plant
• Competitive muscarinic Ach receptor antagonist (blocker)
Scopolamine:
Competitive muscarinic receptor antagonist
• Used to model Alzheimer’s
• Used to look at behavioral roles of muscular receptors
Scopolamine and Object Recognition Test:
- Sample-> Delay-> Drug injection-> Choice
- Drug injection-> Sample-> Delay -> Choice
- Discovered that cholinergic receptors are important for new learning not retrieval of old info
Curare:
- Extract of certain woody vines in South America
- Nicotinic Ach receptor antagonist (competitive)
- Causes paralysis by preventing binding of Ach
Nicotine
- Nicotine acts on nicotinic receptors in brain and enhance memory and attention
- Smoking can make you feel more alert, smoking is common with cognitive deficits (i.e. ADHD)
