Problem
I. While on a tour of a local national park, your guide points out a beautiful mushroom found beneath a fallen tree. They note that it contains a deadly neurotoxin that blocks the activity of voltage-gated potassium channels. How would this affect an action potential and how could consumption of this mushroom lead to death?
i. Identify the area of the action potential that involves VG-K+ channels.
ii. Predict what will happen to the action potential in the presence of the neurotoxin and relate this to what happens at the organism level
II. Depicted is a neuron with two pre-synaptic inputs, "A" and "B". If "neuron A" is stimulated, it will release neurotransmitters that will result in Cl- ion channels opening in the postsynaptic cell. If "neuron B" is triggered, it will release neurotransmitters that will result in Na+ ion channels opening in the postsynaptic cell. Provide a mechanism for each answer.
i. Will the stimulation of "neuron A" cause an EPSP or IPSP in the postsynaptic neuron?
ii. Will the stimulation of "neuron B" cause an EPSP or IPSP in the postsynaptic neuron?
iii. If both neurons A and B are equally stimulated at the same time, is it likely that an action potential will be triggered in the postsynaptic neuron? Explain why or why not.