even a specific ratio between excitation and inhibition can lead to different membrane potentials depending on the absolute magnitude of the two opposing conductances. In fact, since synaptic excitation and inhibition are not the only conductances of a neuron, their contribution to the membrane potential will depend on their magnitude relative to other conductances. Accordingly, the larger their magnitude, the closer the membrane potential of the neuron will approach the equilibrium potential set by the combination of synaptic excitation and inhibition. Finally, because the impact on membrane potential of any current flowing through the membrane is affected in a divisive manner by the conductance of the membrane (Ohm's law), the activation of GABAA receptors, simply by increasing the conductance, can significantly reduce the excitability of a neuron, an effect referred to as "shunting inhibition". This might represent the major inhibitory effect of GABAA receptor activation in those specific cases in which the resting membrane potential is equal to or even more negative than the reversal potential of GABAA receptor-mediated currents. In other words, activation of GABAA receptors may not change the membrane potential or even generate a depolarization and still reduce neuronal excitability. Membrane pumps, by setting intracellular Cl− concentration,
