synaptic transmission Flashcards
(12 cards)
What are the key structures in a chemical synapse?
Presynaptic membrane (axon terminal, vesicles, Ca²⁺ channels), synaptic cleft, and postsynaptic membrane (ion channels).
Q: Briefly outline the process of neurotransmission at a chemical synapse.
A: AP arrives → Ca²⁺ enters → Vesicles release NT → NT crosses cleft → Binds to receptors → Ion channels open → PSP generated → NT removed → Channels close.
Q: What are the two types of gated ion channels and how do they differ?
A: Voltage-gated (respond to depolarization) and transmitter-gated (respond to NT binding).
Q: How do ionotropic and metabotropic receptors differ?
A: Ionotropic open directly; metabotropic work via second messengers.
Q: What is the difference between excitatory and inhibitory synapses?
A: Excitatory: + ions enter → depolarization; Inhibitory: – ions enter → hyperpolarization.
: What is summation in postsynaptic neurons?
Integration of multiple PSPs: Temporal = rapid succession; Spatial = different synapses.
Q: How are neurotransmitters removed from the synapse?
: By degradation (enzymes) or reuptake (transporters in presynaptic cell).
Q: How do agonist and antagonist drugs affect neurotransmission?
A: Agonists mimic/increase NT action; antagonists block/decrease NT action.
What’s the difference between direct and indirect interference by drugs?
Direct affects receptors; indirect affects NT availability (e.g., synthesis, release, reuptake).
: What are common patterns in NT pathways?
: Neurons cluster anatomically and use specific NTs consistently along tracts or nerves.
How are dopamine pathways involved in schizophrenia and Parkinson’s?
Schizophrenia: excess dopamine in MLC pathway; Parkinson’s: dopamine deficiency in NS pathway.
How do dopamine receptors D1 and D2 function differently?
D1 activates second messengers (opens channels); D2 inhibits them (closes channels).
