EP CONNECT ONLINE ACCESS FOR BIOLOGY
20th Edition
ISBN: 9781260494655
Author: Raven
Publisher: MCG COURSE
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Textbook Question
Chapter 42, Problem 1S
Tetraethylammonium (TEA) is a drug that blocks voltage-gated K+ channels. What effect would TEA have on the action potentials produced by a neuron? If TEA could be applied selectively to a presynaptic neuron that releases an excitatory neurotransmitter, how would it alter the synaptic effect of that neurotransmitter on the postsynaptic cell?
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Let’s say the synapses of a neuron’s dendrites are filled with glutamate-gated channels which, when activated by glutamate, cause an excitatory postsynaptic potential (EPSP) in the neuron. In one instance, glutamate is released at all of the synapses simultaneously and this leads to an action potential in the neuron.
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an inhibition in the release of neurotransmitters at the synaptic terminal
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Chapter 42 Solutions
EP CONNECT ONLINE ACCESS FOR BIOLOGY
Ch. 42.1 - Differentiate between subdivisions of the...Ch. 42.1 - Prob. 2LOCh. 42.1 - Explain the roles of the different nervous system...Ch. 42.2 - Contrast the relative concentrations of important...Ch. 42.2 - Prob. 2LOCh. 42.2 - Prob. 3LOCh. 42.3 - Prob. 1LOCh. 42.3 - Prob. 2LOCh. 42.3 - Prob. 3LOCh. 42.4 - Prob. 1LO
Ch. 42.4 - Prob. 2LOCh. 42.4 - Prob. 3LOCh. 42.5 - Describe the organization of the peripheral...Ch. 42.5 - Prob. 2LOCh. 42.5 - Prob. 3LOCh. 42.5 - Prob. 4LOCh. 42 - Data analysis Draw the resulting potentials for...Ch. 42 - Prob. 2DACh. 42 - Which of the following best describes the...Ch. 42 - The ____ cannot be controlled by conscious...Ch. 42 - Prob. 3UCh. 42 - Inhibitory neurotransmitters a. hyperpolarize...Ch. 42 - White matter is ______, and gray matter is...Ch. 42 - During an action potential a. the rising phase is...Ch. 42 - Prob. 7UCh. 42 - Imagine that you are doing an experiment on the...Ch. 42 - The Na+/K+ ATPase pump is a. not required for...Ch. 42 - Prob. 3ACh. 42 - The following is a list of the components of a...Ch. 42 - Prob. 5ACh. 42 - As you sit quietly reading this sentence, the part...Ch. 42 - G proteincoupled receptors are involved in the...Ch. 42 - Tetraethylammonium (TEA) is a drug that blocks...Ch. 42 - Describe the status of the Na+ and K+ channels at...Ch. 42 - Describe the steps required to produce an...Ch. 42 - Prob. 4S
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- An undisclosed drug (Drug A) is a drug that can block voltage-gated K+ channels when being introduced into the bloodstream. Explain the effects of Drug A on the action potentials produced by a neuron. If Drug A could be applied selectively to a presynaptic neuron that releases an excitatory neurotransmitter, analyse how would it alter the synaptic effect of the neurotransmitter on the presynaptic cell. Remark: The word count limit (250 words only), no less than 100 wordsarrow_forwardWhat ion/s is/are most likely to have a high conductance through the Jerrionin channel?arrow_forwardImagine an experiment in which the neurons pictured here are bathed in a solution containing a nerve poison. The presynaptic neuron is stimulated and produces an action potential, but this does not result in a PSP in the postsynaptic neuron. When the experimenter adds some neurotransmitter to the synapse, the postsynaptic neuron still produces no PSP. How does the poison act to disrupt nerve function?arrow_forward
- Photoreceptor cells form glutamatergic synapses onto bipolar cells and when photoreceptor cells are depolarized the release of glutamate into the synapse is increased. One class of bipolar cells, (called OFF bipolar cells) have excitatory glutamate receptors in their post-synaptic specialization. What happens to the membrane potential of OFF bipolar cells when photoreceptors are illuminated?arrow_forwardJohn Hughes and Hans Kosterlitz identified the endorphin receptor in frogs, and concluded that animals have a "built in" opioid system. To make sure that endorphins are truly neurochemicals, which of the following question should we ask these gentlemen? Please select all that apply.a) Are endorphins released in response to presynaptic depolarization? b) Do endorphins interact with postsynaptic receptors? c) Are endorphins found in presynaptic cells? d) Are endorphins subject to reuptake?arrow_forwardWhich of the following is the role of axonal Calcium (Ca2+) channels in neuronal communication at the synapse? a) they inhibit the action potential causing it to stop b) Calcium channels have no role in this process c) by allowing calcium to exit the cell, they promote the propagation of action potential across the synapse by creating depolarization d) by blocking calcium entrance, they mediate the contraction of presynaptic axon to facilitate movement e) when they open, calcium enters the presynaptic terminal, promoting fusion of neurotransmitter vesicles with presynaptic membrane, and release of neurotransmitters to the synaptic cleftarrow_forward
- Given the steps shown below, which of the following is the correct sequence for transmission at a chemical synapse? 1. neurotransmitter binds with receptor 2. sodium ions rush into neuron's cytoplasm 3. action potential depolarizes the presynaptic membrane 4. ion channel opens to allow particular ion to enter cell 5. synaptic vesicles release neurotransmitter into the synaptic cleft O 1, 2, 3, 4, 5 O 5, 1, 2, 4, 3 O 2, 3, 5, 4, 1 O4, 3, 1, 2, 5 O 3, 2, 5, 1, 4arrow_forwardParkinson's Disease Parkinson's disease is neurodegenerative disorder that affects movement. Most people affected with Parkinson's disease demonstrate rigidity, slow movement, and shaking. The symptoms of Parkinson's disease occur when the cells that produce dopamine neurotransmitters die in the brain. Explain how the signal transmission at a synapse in an individual with Parkinson's disease is different than an unaffected individual. Describe the normal process of signal transmission at a synapse. Start with the arrival of an action potential at the axon terminal and include the name of the neurotransmitter that is affected by Parkinson's disease. Explain how the process is different in individuals affected with Parkinson's disease.arrow_forwardI have stimulated a neuron with dopamine for a second followed by treating it with cocaine and calcium chelating agent (which chelates out all calcium from the system making them unavailable for function), what will be the effect of such impulse on generating an action potential in the post-synaptic neuron? Will it be different if I pretreat the set of nerve cells with cocaine and calcium chelating agent followed by stimulating the neuron with dopamine? Justify your answer with proper reasoning in brief.arrow_forward
- Explain what happens when an action potential reaches the axon terminus (terminal) by activating the receptors on the postsynaptic membrane. Explanation addressing the question above When an action potential, or nerve impulse, arrives at the axon terminal, it activates voltage-gated calcium channels in the cell membrane. Which is present at a much higher concentration outside the neuron than inside, rushes into the cell. The Ca2+ allows synaptic vesicles to fuse with the axon terminal membrane, releasing neurotransmitters into the synaptic cleft. The molecules of neurotransmitters diffuse across the synaptic cleft and bind to receptor proteins on the postsynaptic cell. Activation of postsynaptic receptors leads to the opening or closing of ion channels in the cell membrane. This may be depolarizing, making the inside of the cell more positive, or hyperpolarizing making the inside more negative depending on the ions involved. The excitatory and inhibitory postsynaptic potentials…arrow_forwardYou generate action potentials in a neuron bathed in solution in a petri dish by applying a threshold-level depolarizing stimulus near its axon hillock. If the solution surrounding the neuron contained 5mM K+, 150 mM Na+, and 0 mM Ca2+ which of the following would you expect? The neuron would not be able to propagate action potentials down the entire length of the axon The neuron would not release neurotransmitter from the axon terminal The neurons action potentials would have an unusually long duration The neuron would have a resting membrane potential of zeroarrow_forwardThe following steps refer to various stages in transmission at a chemical synapse. 1. Neurotransmitter binds with receptors associated with the postsynaptic membrane. 2. Calcium ions rush into neuron's cytoplasm. 3. An action potential depolarizes the membrane of the presynaptic axon terminal. 4. The ligand-gated ion channels open. 5. The synaptic vesicles release neurotransmitter into the synaptic cleft. Which step occurs first in transmission at a chemical synapse? Ostep 1 occurs first step 2 occurs first step 3 occurs first step 4 occurs first Ostep 5 occurs firstarrow_forward
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