5. Acetylcholine receptors Flashcards
how to sleep better (3)
- sleep consistency: brain loves routine
- red light therapy (we used to wake up at night to tend the fire)
- weighted blankets (increase sleep in children with ADHD)
nervous system separates into 2, then each separates into 2 again, then one of them separates into 2
NERVOUS SYSTEM:
1) Central nervous system
a) brain
b) spinal cord (connects brain and peripheral nervous system)
2) peripheral nervous system: carries messages to and from CNS
a) somatic nervous system: controls voluntary muscles and transmits sensory info to CNS
b) autonomic nervous system: controls involuntary body functions
i) SNS: arouses body to expend energy (fight or flight)
ii) PSNS: calms body to conserve and maintain energy (rest and digest)
does PSNS or SNS:
- constrict pupil
- dilate pupil
- constricts airways
- dilates airways
- stimulates bile release
- stimulate sweat secretion
- increase rate of glycogen to glucose
- stimulates digestive
- decrease digestive
- relax uterus
- vaginal contraction
- relaxes bladder
increases urinary output
- stimulates adrenaline prod
- constrict pupil: PSNS
- dilate pupil: SNS
- constricts airways PSNS
- dilates airways SNS
- stimulates bile release PSNS
- stimulate sweat secretion SNS
- increase rate of glycogen to glucose SNS
- stimulates digestive PSNS
- decrease digestive SNS
- relax uterus PSNS
- vaginal contraction SNS
- relaxes bladder SNS
- increases urinary output PSNS
- stimulates adrenaline prod SNS
SNS vs PSNS
FUNCTION
OVERALL EFFECT (cata or anabolic)
ORGANS AND GLANDS IT ACTIVATES
HORMONES AND SUBSTANCES IT INCREASES
BODY FUNCTIONS IT ACTIVATES
PSYCHOLOGICAL QUALITIES
FACTORS THAT ACTIVATE SYSTEM
SNS:
FUNCTION: defend body against attack
OVERALL EFFECT: catabolic
ORGANS AND GLANDS IT ACTIVATES: brain, muscles, insulin pancreas, thyroid, adrenal glands
HORMONES AND SUBSTANCES IT INCREASES: insulin, cortisol and thyroid hormones
BODY FUNCTIONS IT ACTIVATES: raises BP and blood sugar, increase heat prod
PSYCHOLOGICAL QUALITIES: fear, guilt, sadness, anger, willfulness, aggressiveness
FACTORS THAT ACTIVATE SYSTEM: stress, fear, anger, worry, excessive thinking, too much exercise
PSNS:
FUNCTION: healing, regeneration and nourishing body
OVERALL EFFECT: anabolic
ORGANS AND GLANDS IT ACTIVATES: liver, kidneys, enzyme pancreas, spleen, stomach, small intestine, colon
HORMONES AND SUBSTANCES IT INCREASES: parathyroid hormone, pancreatic enzymes, bile, digestive enzymes
BODY FUNCTIONS IT ACTIVATES: digestion, elimination, immune system
PSYCHOLOGICAL QUALITIES: calmness, contentment, relaxation
FACTORS THAT ACTIVATE SYSTEM: rest, sleep, meditation, relaxation therapies, feelings of being loved
which types of neurons and neurotransmitter for somatic nervous system, PSNS and SNS?
somatic:
- cholinergic neurons –> acetylcholine
PSNS: cholinergic neurons for both pre and post-ganglionic
- acetylcholine for both!
SNS:
- cholinergic and ACh for pre-ganglionic
- adrenergic and norepinephrine for post-ganglionic OR epinephrine via bloodstream
what are the 5 categories of neurotransmitters? + examples ish
- acetylcholine (PSNS and pre-ganglionic SNS)
- amino acids: glutamate, GABA, glycine
- Monoamines: indolamines (serotonin) and catecholamines (dopamine, NE, E)
- purines: adenosine
- peptides: opioid
Acetylcholine
- found where (4)
- use to treat (2)
- 2 types of receptors!
- found in motor neuron (muscles), brain, SNS (pre-ganglionic) and PSNS (both ganglionic and terminal)
- used to treat Alzheimer’s disease and dementia
1) ionotropic: nicotinic receptors
2) metabotropic: muscarinic receptors
whats the difference between nicotinic receptors and muscarinic receptors?
- slow or fast response?
NICOTINIC
- ionotropic –> ion channels!
- multimers, has 2 domains: extracellular (Ach binds) and transmembrane (where ions pass through)
- mediate rapid effect!
MUSCARINIC:
- metabotropic –>activation of G proteins
- extracellular: neurotransmitter binding site vs intracellular: G-protein binding set
- slower response
TOBACCO (monograph):
- SCIENTIFIC NAME:
- PART USED:
- MODE OF ADMINISTRATION:
- BIOACTIVE COMPOUND:
- COMPOUND CLASS:
- USES: (5)
- SCIENTIFIC NAME: nicotiana tabacum (tobacco)
- PART USED: leaves
- MODE OF ADMINISTRATION: insufflation (blow it in someone’s nose) OR inhalation (smoke it)
- BIOACTIVE COMPOUND: nicotine
- COMPOUND CLASS: alkaloid
USES: - entheogenic (makes you feel high)
- stimulant/sedative
- antispasmodic
- antinausea
- expectorant: makes you spit
Nicotine
- acts as what? Specific!
- addictive?
- causes overflow of what?
- activates SNS or PSNS? –> stimulates release of what neurotransmitter?
- acts as receptor agonist! (acts as Ach) –> at a7 nicotinic acetylcholine receptors (a7nAChR)
*a7 is the most abundant nAChR in the CNS - HIGHLY addictive –> directly stimulates ACh receptors on dopamine containing neurons
- causes overflow of dopamine in reward centers of brain –> dopamine = root of all addictions –> affects limbic system
- activates SNS –> stimulates release of epinephrine
explains 4 steps of ACh synapse ish
- Action potential arrives in pre-synaptic neuron
- vesicle fuses with plasma membrane
- neurotransmitter/ACh from vesicle released into synaptic cleft
- Ach binds to nicotinic acetylcholine receptors (ionotropic) (nAChR) –> AP continues to next neuron
what are the 3 ways to get rid of neurotransmitters? (ie Ach)
- enzymatic degradation: acetylcholinesterase breaks down ACh
- reuptake by presynaptic neuron
- diffusion away from synapse
- what is a PAM?
- is nicotine a PAM?
- potential therapeutic uses nAChR (6)
- positive allosteric modulators –> bind at other sites on receptor
- nicotine is NOT a PAM –> nicotine is an ACh agonist! (binds where ACh usually binds)
- cognitive disorders
- schizophrenia
- Alzheimer’s disease
- epilepsy
- inflammation
- pain
- where are a7nAChRs abundantly expressed in the brain? (5)
- dysfunction of a7nAChR associated with what? (5)
- regions underlying cognition, memory, sensory processing, attention and reward
- psychiatric and neurological diseases: schizophrenia, Alzheimer’s disease, ADHD, addiction, Parkinson’s disease
how can nicotine/n7AChR induce addiction? in which 4 pathways + 1 area of the brain ish?
- nicotine on n7AChR –> can innervate dopaminergic neurons (Dopamine!) = addiction!
- in ventral tegmental area (in brainstem) (where nicotine binds, where addiction happens) +
- mesocortical
- nigrostriatal pathway
- tubero-infundibular pathway
- mesolimbic pathway
(aka cortical-limbic pathway)
explain mechanisms of what happens fo a7nAChR when you’re addicted to nicotine (4 steps)
- craving: no nicotine in system, receptor is closed
- smoke cigarette: in present of nicotine (ACh agonist), receptor opens and lets signal through –> leads to release of dopamine = reward
- cigarette just finished: receptor is desensitized and does not respond to more nicotine –> receptor is closed
- long term smoking increases craving: more receptors are formed with long-term exposure to nicotine: brain increases receptors bc R are stimulated not by brain (but by cigarette) –> so takes more nicotine to reach same stimulus
TOBACCO
- curing and aging of tobacco leaves generates what?
- starch is converted to _______ –> which _________ proteins –> ___________ into (A)?
- inhalation of (A) is a major contributor to (2)
- manufacturers use ________ to do 3 things in tobacco industry
- generates carcinogenic tobacco-specific nitrosamines (TSNAs)
- starch is converted to sugar, which glycates proteins –> oxidizes into advanced glycation endproductions (AGEs)
- inhalation of AGEs is a major contributor to atherosclerosis and cancer
- use additives to enhance flavour, reduce harshness, and increase addictiveness (ammonia)
Definitions:
INSUFFLATION:
EXPECTORANT:
STIMULANT:
DEPRESSANT:
ENTHEOGENIC:
INSUFFLATION: act of blowing something into a body cavity
EXPECTORANT: promotes secretion of sputum
STIMULANT: causing raised levels of physiological or nervous activity in body
DEPRESSANT: causing reduced functional or nervous activity
ENTHEOGENIC: drug that causes one to become inspired or to experience feelings of inspiration, often in a religious or spiritual manner
Fly agaric (monograph)
- SCIENTIFIC NAME:
- PART USED:
- MODE OF ADMINISTRATION:
- BIOACTIVE COMPOUND:
- COMPOUND CLASS:
- USES: (4)
- SCIENTIFIC NAME: amanita muscaria
- PART USED: entire mushroom
- MODE OF ADMINISTRATION: ingestion
- BIOACTIVE COMPOUND: muscarine
- COMPOUND CLASS: alkaloid
USES: - entheogenic
- hallucinogen
- antinausea
- expectorant
muscarine
- how much is found in amanita muscaria?
- acts as what?
- causes activation of what?
- why is it super toxic?
- can cause (2)
- used to treat (3)
- what is an antidote ish?
- trace amounts!
- mimics actions of ACh (ACh agonist) on muscarinic acetylcholine receptors (metabotropic receptors)
- cause profound activation of PSNS.
- not degraded by acetylcholinesterase, explaining its toxicity
- can cause circulatory collapse and death
- glaucoma (decrease pressure in eye), hirschprung disease (congenital megacolon), and dry mouth
- treated with atropine! an antagonist of muscarinic receptors
amanita poisoning:
- fatal dose?
- predictable symptoms?
- symptoms (a lot)
NOT ON EXAM
15 caps (no size mentioned)
- unpredictable: based on habitat and amount eaten
- nausea, stomach aches, vomiting
- exceessive salivation, loss of balance, twitching, trembling
- dissociative effects similar to Z-drugs like ambien and lumesta (sleeping drugs)
- changes in perception (depth and size)
- euphoria, relaxation, hypnotic, sedative
what is the main psychoactive compound in amanita muscarita?
- what is its pre-drug? –> cause what?
- compound acts as what?
- responsible for which effects of amanita poisoning?
- muscimol! (not muscarine) and its pre-drug ibotenic acid –> cause of hallucinations and toxicity
- muscimol is a potent selective GABA receptor agonist (GABA = relaxant, inhibitor)
- responsible for drunkenness, sedative, euphoric, and dissociative effect + sedative, hypnotic, depressant and hallucinogenic psychoactivity
ibotenic acid
- potent agonist of (2)
- responsible for which symptoms (3) associated with amanita ingestion
- how is it converted to the psychoactive compound of amanita?
- potent agonist of N-methyl-D-aspartate (NMDA) and metabotropic glutamate receptors
- nausea, stomach cramps, vomiting
- undergoes decarboxylation in kidneys to generate muscimol (psychoactive compound)
what are 3 main plants used in divination + their main compounds?
- angel’s trumpets
- brugmansia spp.
- tropane alkaloids: scopalamine, hyoscymine, atropine –> very potent! - Jimson weed
- datura stramonium
- tropane alkaloids: scopalamine, hyoscymine, atropine - morning glory
- ipomoea tricolor
- ergoline alkaloids: ergonovine, ergine
