Mоdule 5 A pоstsynаptic neurоn receives excitаtory input from glutаmate-releasing neurons and inhibitory input from GABA-releasing neurons. GABA receptors normally open Cl⁻ channels. A mutation prevents the GABA receptors from opening these channels. Neurotransmitter release and the excitatory synapses function normally. Under normal conditions, explain how GABA affects the postsynaptic membrane potential and the likelihood of an action potential. (4 points) With the mutation, predict how the postsynaptic neuron will respond when excitatory and inhibitory inputs arrive at the same time. Explain your reasoning. (6 points) Suppose the presynaptic neurons respond by releasing more GABA. Would this restore normal inhibition? Explain why or why not. (5 points) A different mutation prevents GABA from being released but leaves the postsynaptic GABA receptors functional. Would you expect a similar effect on the postsynaptic neuron? Explain the important difference between the two mutations. (5 points)