For the following questions, assume a hypothetical postsynaptic neuron has three presynaptic inputs: neurons X, Y, and Z. Also, assume neuron Z is excitatory. What changes would you expect at the postsynaptic neuron when neuron X is stimulated? (Remember that the postsynaptic neuron becomes hyperpolarized by neuron X.) A) increased P_Na+ and P_K+ B) increased P_K+ or P_Cl- C) increased P_A- D) increased P_Ca2+ E) none of these

Question

Quizplus · Accepted Answer

When neuron X is stimulated and causes hyperpolarization in the postsynaptic neuron, only the inhibitory neurotransmitters (GABA or glycine) will be released. This will lead to an increase in potassium (K+) or chloride (Cl-) ion channels opening, causing hyperpolarization and a decrease in the neuron's firing rate. However, the activation of neuron X would not directly affect the levels of sodium (Na+) or calcium (Ca2+) ions. Therefore, neither A nor D can be the correct answer. Choice C is also incorrect, as there isn't enough context to suggest that neuron X is releasing the excitatory neurotransmitter acetylcholine (ACh).

For the Following Questions, Assume a Hypothetical Postsynaptic Neuron Has