Neurotransmitters & Psychopharmacology Flashcards
What are agonist drugs?
A drug that facilitates the effects of a particular neurotransmitter on the postsynaptic cell.
what are antagonist drugs?
A drug that opposes or inhibits the effects of a particular neurotransmitter on the postsynaptic cell.
what are sites of action?
locations at which molecules of drugs interact with molecules located on on in cells, this affecting some biochemical processes of these cells
what are the main 5 sites of action for neurotransmitters?
- Production
- Release
- Receptors
- Reuptake
- Storage
how do drugs effect post-synaptic receptors?
Drugs bind with these receptors, just as the neurotransmitter would, this drug can serve as either an agonist or an antagonist.
Look at indirect agonists/antagonists at receptor sites
What are the 2 processes after a neurotransmitter is released?
- Molecules of the neurotransmitter are taken back into the terminal button through the process of reuptake
- They are destroyed by an enzyme.
What is the nocebo effect?
where people can feel worse after an intervention that
should have no ill effects
Which is the primary excitatory neurotransmitter?
glutamate
what are the primary inhibitory neurotransmitters?
GABA or glycine
Where is acetylcholine primary found?
The primary neurotransmitter secreted by the efferent axons of the CNS
What is Acetylcholine (ACh) used in?
Muscular movement, REM sleep, perceptual learning and memory
what is the name of the synapses ACh binds to?
cholinergic
What is the primary ion used in cholinergic synapses?
Ca2+ =presynaptic
Na+ =postsynaptic
How do Ca2+ ions help the release of neurotransmitters in cholinergic synapses?
Ca2+ is absorbed into the presynaptic cell and then ACh is released.
How do Na+ ions help the transmission of nerve signals in cholinergic synapses?
Sodium ions diffuse into the postsynaptic membrane causing depolarisation, which initiates an action potential.
What happens to ACh after it is released into the synapse?
It is broken down by enzymes and the products are reabsorbed by the pre-synaptic cell.
what are the 2 types of receptors for ACh?
- an ionotropic acetylcholine receptor stimulated by nicotine
- a metabotropic acetylcholine receptor
what effects muscarinic receptor?
Stimulated by muscarine and blocked by atropine
what effects a nicotinic receptor?
stimulated by nicotine and blocked by curare (paralysis).
which 2 poisons effect acetylcholine?
Botulinum toxin - An acetylcholine antagonist; prevents
release by terminal buttons.
Black widow spider venom - A poison produced by the black widow spider that triggers the release of acetylcholine causing convulsions - agonist
Which 4 chemicals make up the monoamines neurotransmitters?
Dopamine, norepinephrine, epinephrine, and serotonin
d: addiction
: a state in which an organism engages in compulsive behaviour, behaviour is reinforcing (rewarding, pleasurable), loss of control for limiting intake
what is the dopamine pathway associated with addiction?
Reward pathway starts in VTA - ventral tegmental area. Then goes to nucleus accumbens and then the prefrontal cortex.
What was found with rats preference of heroine insertion and the brain?
Self - administration of heroine either into the VTA or just the body. The rats like both, but refereed the VTA.
d: tolerance
A state in which organism no longer responds to the same dose of a drug
d: dependence
A state in which organism functions normally only in the
presence of a drug
do addiction and dependence share a neural circuit?
no - it is possible to be dependent on the morphine, without being addicted to it.
What is the nigrostriatal system?
a dopamine pathway, starts in the substantia nigra and terminates in the basal ganglia : plays a role in the control of movement - goes wrong in Parkinson’s
Which class A drug inhibits the reuptake of dopamine?
cocaine
what does serotonin play a role in?
regulation of mood, the control of eating, sleep, dreaming, arousal and involved in the regulation of pain.
1. appetite
2. sleep
3. memory and learning
4. temperature regulation
5. cardiovascular function
6. muscle contraction
7. endocrine regulation
8. depression
How does heroine effect the presynaptic cell?
Opium/heroin tells the ventricles/vesicles to produce more dopamine
How does LSD have an effect?
LSD stimulates centres of the sympathetic nervous system in the midbrain, and also has a serotonin-blocking effect
How does MDMA work?
Has excitatory and hallucinogenic effects.
1. Prevent reuptake
2. Bring more serotonin to the synapse
What is the sceincey representation of serotonin?
5-HT
How do anti-depressants work?
increase serotonin levels at the synapse by blocking the reuptake of serotonin into the presynaptic cell
how does norepinephrine work as a hormone?
gives us energy in fight or flight situations
how is norepinephrine used to treat mental disorders?
Medications that inhibit the reuptake of NE can be effective to treat depression. In addition, elevated NE levels are found in patients experiencing mania
Is GABA an excitory of inhibitory neurotransmitter?
most important inhibitory neurotransmitter
Which mental disorders is an an imbalance in GABA associated in?
bipolar disorder, schizophrenia and anxiety
What are come of the most common anxiolytics?
Benzodiazepine, Valium (diazepam), Xanax (Alprazolam)
How do anxiolytic drugs work?
an indirect agonist for the GABAA receptor
How does the paralytic arrow-poison curare act?
by blocking transmission at the Acetylcholine transmitters, stooping transmission at the neuromuscular junction connecting motor nerves to muscles
what kind of synapses are thought to be the main memory-storage of the brain?
Modifiable synapses - i.e. capable of increasing or decreasing in strength.
