Neuroscience: Synaptic Transmission Concepts

Synapse

Electrical synapses provide very fast transmission, while chemical synapses are somewhat slower.

The presynaptic neuron transmits information to the postsynaptic neuron.

<p>Chemical synapses generate postsynaptic potentials (PSPs).</p> Signup and view all the answers

<p>Synaptic integration</p> Signup and view all the answers

<p>Dendritic sodium channels may carry electrical signals from the soma outward along the dendrites.</p> Signup and view all the answers

<p>Inhibitory synapses take the membrane potential away from the action potential threshold.</p> Signup and view all the answers

<p>A hyperpolarizing IPSP occurs when the membrane potential is less negative than -65 mV.</p> Signup and view all the answers

<p>Shunting inhibition involves the inhibition of current flow from the soma to the axon hillock.</p> Signup and view all the answers

<p>Chemical synaptic transmission's diversity explains complex behavior and the impact of drugs and disorders.</p> Signup and view all the answers

<p>Electrical synapses are formed by gap junctions, specifically connexons made up of six connexins, allowing the flow of ions between cells.</p> Signup and view all the answers

<p>Gray's Type I synapses are asymmetrical and excitatory, while Gray's Type II synapses are symmetrical and inhibitory.</p> Signup and view all the answers

<p>The steps include neurotransmitter synthesis, loading into vesicles, vesicle fusion to the presynaptic terminal, release into the synaptic cleft, binding to receptors, eliciting a response, and removal from the cleft.</p> Signup and view all the answers

<p>Neurotransmitter types include amino acids (e.g., Glutamate), amines (e.g., Dopamine), and peptides (e.g., substance P).</p> Signup and view all the answers

<p>Neurotransmitter receptors bind to neurotransmitters, eliciting biochemical or electrical responses in the postsynaptic cell.</p> Signup and view all the answers

<p>The NMJ was pivotal in establishing key principles of synaptic transmission due to its accessibility and functionality.</p> Signup and view all the answers

<p>An axosomatic synapse is formed between an axon and the cell body, while an axodendritic synapse connects an axon to a dendrite.</p> Signup and view all the answers

<p>Neurotransmitters are cleared from the synaptic cleft to terminate the signal and prevent continuous activation of the postsynaptic cell.</p> Signup and view all the answers

<p>IEPSP = N x po x g x (Vm - EEPSP)</p> Signup and view all the answers

<p>Desensitization refers to the decreased responsiveness of neurotransmitter receptors after prolonged exposure to a neurotransmitter.</p> Signup and view all the answers

<p>Receptor agonists mimic the actions of naturally occurring neurotransmitters.</p> Signup and view all the answers

<p>EPSP summation allows for multiple synaptic potentials to combine, producing significant depolarization in the postsynaptic neuron.</p> Signup and view all the answers

<p>Dendritic length constant determines how far depolarization can spread along the dendrite before it dissipates.</p> Signup and view all the answers

<p>The two types are spatial summation, where EPSPs occur simultaneously at different locations, and temporal summation, where EPSPs occur rapidly at the same synapse.</p> Signup and view all the answers

<p>The driving force is affected by factors such as the reversal potential of EPSPs and the membrane potential.</p> Signup and view all the answers

<p>Neurotransmitter recovery mechanisms are vital for modulating synaptic transmission and preventing excessive signaling.</p> Signup and view all the answers

<p>Exocytosis is the process by which vesicles release their contents into the synaptic cleft, enabling neurotransmitter communication between neurons.</p> Signup and view all the answers

<p>'Quantum' refers to the indivisible unit of neurotransmitter released from a synaptic vesicle during neurotransmission.</p> Signup and view all the answers

<p>Ionotropic receptors are transmitter-gated ion channels that allow ions to flow across the membrane, leading to changes in membrane potential.</p> Signup and view all the answers

<p>Miniature postsynaptic potentials serve as indicators of the quantal release of neurotransmitters and help determine the efficacy of synaptic transmission.</p> Signup and view all the answers

<p>Increased intracellular calcium concentration ([Ca2+]i) stimulates the exocytosis of vesicles, leading to the release of neurotransmitters.</p> Signup and view all the answers

<p>An EPSP results from a transient depolarization of the postsynaptic membrane caused by the release of an excitatory neurotransmitter.</p> Signup and view all the answers

<p>EPSPs cause depolarization of the postsynaptic membrane, while IPSPs lead to hyperpolarization, counteracting excitatory signals.</p> Signup and view all the answers

<p>Quantal analysis is a method used to determine the number of synaptic vesicles released during neurotransmission by assessing the size of EPSPs.</p> Signup and view all the answers

<p>Endocytosis is the process that recovers the vesicle membrane after neurotransmitter release, allowing for the recycling of synaptic vesicles.</p> Signup and view all the answers

<p>The average number of channels opened by an agonist determines the total conductance, thereby influencing the magnitude of EPSPs.</p> Signup and view all the answers