L12 - Neuropharmacology Flashcards
What does neuropharmacology study?
How chemicals like drugs and neurotransmitters affect neuronal function in the nervous system
What are endogenous chemicals in neuropharmacology?
Neurotransmitters
What are exogenous chemicals in neuropharmacology?
Drugs
What role do calcium channels play in neurotransmitter release?
Calcium influx triggers vesicle fusion with the presynaptic membrane, which releases neurotransmitters into the synaptic cleft.
How are neurotransmitters cleared from the synaptic cleft?
Through reuptake by transporters, enzymatic breakdown or diffusion away from the cleft
What is the synaptic cleft?
Small gap between presynaptic and postsynaptic neurons where neurotransmitter transmission occurs
How do neurotransmitters binding to receptors affect the postsynaptic neuron?
It can cause either excitation (EPSP) or inhibition (IPSP) depending on the receptor type
What is the role of ionotropic receptors?
They directly regulate ion fluxes through ion channels
What happens when acetylcholine binds to a nicotinic receptor?
Sodium channels open, causing depolarisation (Excitatory Postsynaptic Potential - EPSP).
How does GABA binding to GABA-A receptors affect the cell?
Chloride channels open, causing hyperpolarisation (Inhibitory Postsynaptic Potential IPSP)
What is the difference between metabotropic and ionotropic receptors?
Metabotropic receptors regulate intracellular metabolic reactions often through G-protein mediated systems and have slower, longer-lasting effects.
Ionotropic receptors directly regulate ion fluxes through ion channels causing rapid ad short-lasting effects
Give an example of a metabotropic receptor?
Muscarinic acetylcholine receptors
what are 3 examples of ionotropic receptors?
Glutamate receptors, GABA-A receptors, nicotine acetycholine receptors
Name a serotonin receptor that’s ionotropic?
the 5HT-3 receptor
What is a receptor agonists?
A substance that mimics the action of the native neurotransmitter at a receptor
What is a receptor antagonist?
Substances that bind to a receptor but don’t activate it, blocking neurotransmitter binding
What are Barbiturates and how do they differ from BZs in terms of safety?
Barbiturates are drugs that act as CNS depressants
They have a higher risk of dependence and fatal respiratory depression compared to BZs
How do BZs modulate GABA-A receptors?
They enhance the effect of GABA by binding to an allosetric site (location on the receptor that’s separate from the active site), increasing chloride influx and inhibition
What does the Diazepam Binding Inhibitor (DBI) do?
DBI is an endogenous modulator of GABA-A receptor fucntion, affecting inhibition in the brain
What are presynaptic receptors?
receptors located on the neurone terminals that modulate neurotransmitter release
What’s the role of autoreceptors?
The provide negative feedback to reduce neurotransmitter release, synthesis or storage
How do heteroreceptors differ from autotrceptros
Heterorecptors modulate neurotransmitter release of another neuron and autoreceptos modulate thier own neuron’s transmitter release
Can heteroreceptors be excitatory?
Yes - heteroreceptors can enhance neurotransmitter release in the second terminal
What do Monoamine Oxidase Inhibitors (MAOIs) do?
They inhibit monoamine oxadise enzymes, preventing neurotransmitter breakdown and increasing levels in the synaptic cleft
