Answer: Cl moves in; GABA is inhibitory
Explanation:
For a neuron to fire, it has to reach what is called a 'threshold' that is more positive than the resting membrane potential. When GABA binds, Cl- flows inside the neuron and hyperpolarizes the membrane, AKA making it more negative. That means when the neuron wants to reach the threshold, it has to make an even bigger jump from its negative state to the more positive threshold. This inhibits the neuron.
