Pharmacology CNS Flashcards
(47 cards)
What are the 5 different types of synapses
1) Excitatory ion channel synapses: Increase the likelihood of action potentia;
2) Inhbitory ion channel synapses: Decrease the likelihood of action potential
3) Non channel synapses: Non-Channel Synapses work by using special receptors on the cell membrane that activate enzymes inside the cell instead of opening ion channels. These enzymes then send signals inside the cell to create a response. Think of it like a doorbell—instead of opening a door directly (like ion channels), it rings a bell inside to trigger an action.
4)Neuromuscular Junctions → Synapses between motor neurons and muscle cells using acetylcholine (ACh); always excitatory.
5)Electrical synaspses:Direct connection between cells through shared proteins, allowing fast action potential transmission
Explain Excitatory synapses
makes the next neuron more likely to fire by depolarizing it (making it more positive).Neurotransmitters (like acetylcholine or glutamate) are released from the presynaptic neuron into the synaptic cleft.
They bind to sodium (Na⁺) channels on the postsynaptic membrane.
This opens sodium channels, allowing Na⁺ ions to flow in, making the inside of the neuron more positive.
This depolarization makes an action potential (nerve signal) more likely.
List typical excitatory neurotransmitters
acetylcholine, glutamate, aspartate, or catecholamines.
Explain how inhabitory synapses work
The neurotransmitter at inhibitory synapses hyperpolarizes the postsynaptic membrane.
These synapses have neuroreceptors that are chloride channels. When the channels open, negative ions flow in causing a local hyperpolarisation and making an action potential less likely.
Give neurotransmitter examples of inhibitory synapses
GABA and Glycine
How do drugs work on the nervous system
1)Synthesis: increase/block neurotransmitters
2)Packaging: affect how neurotransmitters are stored in vesicles
3)Release: Heteroreceptors meaning influence other neurotransmitters to increase or decrease release and Autoreceptors: Drugs can inhibit or enhance release by affecting feedback receptors on the same neuron
4)Actions at Receptor
5)Reuptak
6) breakdown: Some drugs inhibit enzymes that break down neurotransmitters, prolonging their effects
List the different types of receptors and their functions
adrenergic,Dopaminergic
GABAergic,Glutaminergic Histaminergic, Cholinergic
Opioid,Serotonergic,Glycinergic
Adrenergic receptor function
Responds to epinephrine & norepinephrine (fight-or-flight response).
Dopaminergic receptor function
Binds dopamine, regulating mood, movement, and reward.
GABAergic receptor function
Responds to GABA, the main inhibitory neurotransmitter (calming effect).
Glutaminergic receptor function
Binds glutamate, the main excitatory neurotransmitter (learning & memory).
Histaminergic receptor function
Uses histamine, involved in wakefulness and immune response
Cholinergic receptor function
Binds acetylcholine (ACh), important for muscle movement & memory.
Opioid receptor function
Responds to endorphins & opioids, regulating pain and pleasure.
Serotonergic receptor function
Uses serotonin, controlling mood, sleep, and appetite.
Glycinergic receptor function
Uses glycine, an inhibitory neurotransmitter that helps with motor control & reflexes.
Mechanism of ADHD
Excess dopamine reuptake, decreased dopamine availability
Reduced norepinephrine levels
Lower serotonin levels may contribute as well.
refrontal cortex dysfunction
The prefrontal cortex which controls executive functions like attention, planning and impulse control is less active in the ADHD brain.
Increased cortisol and stress sensitivity
Many ADHD brains show higher cortisol responses to stress, making emotional regulation more difficult
May contribute to higher anxiety and emotional reactivity
What do CNS stimulants do and what are they used for
medicines that speed up physical and mental processes
-used to treat ADHD
-narcolepsy
Good and bad side of CNS stimulants
increased alertness, improved concentration, and enhanced energy. However, their therapeutic use is restricted because of potential side effects like insomnia, increased heart rate, high blood pressure, anxiety, and the risk of dependence or abus
How do CNS stimulants work
The exact mechanism of action is not clear, but it may involve stimulating the cerebral cortex and increasing the activity of norepinephrine, dopamine, and other catecholamines in the prefrontal cortex, which control attention and impulse regulation.
list 3 CNS stimulants
-Caffiene=blocks adenosine receptor
-Amphetamine
-Methylphenidate
How does amphetamine
1) forces neruons to release dopamin into the synapse
2)makes the vesicles dump out more dopamine
3)Blocks MAO enzyme from destroying it
4)Reverses the dopamine transporter, making it push dopamine out instead of taking it back i
CNS stimulants side effects
palpitations, cardiac dysrhythmias, hypertension, nervousness, nausea
Highly addictive and widely abused outside therapeutic therapy (especially methamphetamine)
Why might doctor recommend a nonstimulant medication forADHD.
Stimulant medications didn’t work.
Stimulant medications had intolerable side effects.
A child withADHDmight have another disorder as well.
Stimulants could be risky for a teenager with substance-use problems or a history of drug use.
