Chapter 5: Synaptic Transmission Flashcards
What is synaptic transmission?
The process of information transfer at a synapse, crucial for neuron communication.
What are the steps involved in neurotransmitter synthesis for amino acid and amine neurotransmitters?
Synthesis involves metabolic precursor conversion by specific enzymes, transported to the axon terminal for rapid synthesis.
How are peptide neurotransmitters synthesized and stored?
Synthesized in the cell body, processed in the Golgi apparatus, and transported to the axon terminal in secretory granules.
Compare the storage of amine and amino acid neurotransmitters to peptide neurotransmitters.
Amine and amino acid neurotransmitters are stored in synaptic vesicles at the axon terminals, while peptide neurotransmitters are stored in secretory granules transported from the cell body.
What mechanism ensures the rapid and precise release of neurotransmitters?
The localization and concentration of neurotransmitters inside vesicles facilitated by transporters and enzymes.
How was the nature of synaptic transmission debated and eventually proven?
Initially hypothesized as electrical, proven chemical by studies in the 1950s by Edwin Furshpan, David Potter, and Akira Watanabe.
What are electrical synapses and how do they function?
Electrical synapses allow direct ionic current transfer between cells through gap junctions, enabling rapid and reliable transmission.
Describe the structure and function of chemical synapses.
Characterized by a synaptic cleft, presynaptic elements with synaptic vesicles, and postsynaptic elements with neurotransmitter receptors.
How do neurotransmitter receptors and effectors contribute to synaptic transmission?
Transmitter-gated ion channels and G-protein-coupled receptors convert chemical signals into electrical or biochemical responses.
What roles do autoreceptors play in synaptic transmission?
Autoreceptors regulate neurotransmitter release by inhibiting further release and synthesis when activated by the neurotransmitter.
How is neurotransmitter recovery and degradation achieved?
Through diffusion, reuptake into the presynaptic neuron, degradation in the synaptic cleft, or uptake by glial cells.
Explain the importance of synaptic integration in neural processing.
Synaptic integration allows a neuron to combine multiple synaptic potentials, determining whether to fire an action potential.
What is the role of dendritic properties in synaptic integration?
Dendritic cable properties and the presence of voltage-gated ion channels influence the effectiveness of synaptic signals.
How does the neuromuscular junction exemplify synaptic transmission?
It shows fast, reliable transmission with large EPSPs, highlighting mechanisms of synaptic communication.
Describe the basic requirements for chemical synaptic transmission.
Includes neurotransmitter synthesis, vesicle release, postsynaptic response, neurotransmitter removal, and rapid processing.
What is the significance of neurotransmitter types in synaptic transmission?
Different neurotransmitters and their receptors enable diverse synaptic functions and speeds of transmission.
How does the process of neurotransmitter release occur?
Triggered by action potential-induced Ca2+ influx, leading to vesicle fusion with the presynaptic membrane and neurotransmitter release.
What distinguishes fast synaptic transmission from slow synaptic transmission?
Fast transmission is mediated by amino acids and some amines for quick responses, while slow transmission involves peptides for prolonged effects.
