Assume presynaptic excitatory neuron A terminates on a postsynaptic cell near the axon hillock and presynaptic excitatory neuron B terminates on the same postsynaptic cell on a dendrite located on the side of the cell body opposite the axon hillock. Explain why rapid firing of presynaptic neuron A could bring the postsynaptic neuron to threshold through temporal summation, thus initiating an action potential, whereas firing of presynaptic neuron B at the same frequency and the same magnitude of EPSPs may not bring the postsynaptic neuron to threshold.
Trending nowThis is a popular solution!
Chapter 4 Solutions
Human Physiology: From Cells to Systems (MindTap Course List)
Additional Science Textbook Solutions
Human Physiology: An Integrated Approach (7th Edition)
Genetic Analysis: An Integrated Approach (3rd Edition)
Microbiology with Diseases by Body System (4th Edition)
Microbiology: An Introduction
Campbell Biology in Focus
Campbell Biology: Concepts & Connections (9th Edition)
- which one of the following statements is incorrect? a. temporal summation occurs when a single synaptic input is activated twice in succession, with the second postsynaptic potential occurring before the first postsynaptic potential is over. b. blocking voltage-gated k* channels in the presynaptic membrane of a typical chemical synapse is likely to reduce the amount of neurotransmitter released in response to a single action potential in the presynaptic axon. c. in the optic tectum of the hunting rattlesnake, spatial summation is used to combine inputs from visual and thermoreceptive layers in order to make a decision whether to strike at a mouse-like object. d. a single type of neurotransmitter can have different postsynaptic actions depending on the type of receptor to which it binds.arrow_forwardThe correlation between neurons can explain the basis of the synaptic modification, that is, how much they can connect to each other or if they are not synchronized, how much they can lose or weaken their connections. • Draw a picture of an excitatory synapse such as glutamatergic with its receptors between the pre- and postsynaptic neuron. • Briefly explain what mechanisms involve neuronal plasticity and why synapses are enhanced or weakened.arrow_forwardIf a pre-synaptic cell releases a large amount of excitatory neurotransmitter into the synaptic cleft, how will that affect the PSPs? Does that large release ensure that the postsynaptic cell will initiate an action potential, and what role does the axon hillock play in this process/decision?arrow_forward
- Because the long axons of neurons look like electrical wires, and both neurons and electrical wires conduct electricity, it is tempting to equate the two. Compare and contrast the functioning of axons and electrical wires in terms of their structure and the nature of the electrical signals they conduct. Please include references.arrow_forwardIn the central nervous system there may be many synaptic inputs on a postsynaptic neurons. How does the postsynaptic neuron respond to the many presynaptic inputs?arrow_forwardToxins from the cone snail block glutamate receptors in the postsynaptic membrane. What specifically will this action inhibit?arrow_forward
- When an inhibitory neurotransmitter such as GABA opens cl– channels in the plasma membrane of a postsynaptic neuron, why does this make it harder for an excitatory neurotransmitter to excite the neuron?arrow_forwardWhich of the statements below describe a situation in which the change in membrane potential above could cause the firing of an action potential? Select all that apply. ___If the potential is counteracted by an IPSP. ___If the potential is strong enough to bring the axon hillock to threshold. ___If the neuron is in the relative refractory period. ___If the potential is supplemented by a simultaneous (or near-simultaneous) EPSP.arrow_forwardWhat is a typical value for an inhibitory post synaptic potential? Why is it inhibitory?arrow_forward
- Why does neuronal function require the voltage-gated K+ channels to open moreslowly than the voltage-gated Na+ channels and how would you expect the voltage-gated K+ channels to affect the shape of an action potential curve?arrow_forwardImagine you are studying the activity of neurons in a mouse that is awake and interacting with other mice. If you knew that an excitatory post-synaptic potential (EPSP) occurred, you _______ predict whether it would increase or decrease the likelihood of a particular behavior The neurons you are studying could be releasing ___________ because it is the major excitatory neurotransmitter in the brain that generally depolarizes postsynaptic neurons. If you wanted to study what happens when neurons are unable to make this particular neurotransmitter you could use ___________, which is a method that prevents your gene of interest from being translated. Group of answer choices A) Could not; GABA; Electron microscopy B) Could; Glutamate; Anterograde tracing C) Could; GABA; Immunohistochemistry D) Could not; Glutamate; Antisense oligonucleotidesarrow_forwardThe absolute refractory period of an action potentialA. only ensures one-way travel down an axon.B. only allows a neuron to ignore a second signal sent that closely follows the first.C. only prevents summation of action potentials within the axonD. ensures one-way travel down an axon and allows a neuron to ignore a second signal sent that closely follows the firstE. ensures one-way travel down an axon, allows a neuron to ignore a second signal sent that closely follows the first, and prevents summation of action potentials within the axonarrow_forward
- Human Physiology: From Cells to Systems (MindTap ...BiologyISBN:9781285866932Author:Lauralee SherwoodPublisher:Cengage Learning