In Adult Neurons, There Is a Higher Concentration of Chloride

Multiple Choice

In adult neurons, there is a higher concentration of chloride outside the cell than inside the cell. During development intracellular chloride concentrations are much higher such that GABA causes excitation of the postsynaptic neuron. Why could changing the Cl^- concentration result in excitation?

A) E_Cl is now > action potential threshold.
B) E_Cl is now < action potential threshold.
C) There is a smaller Ca²⁺ conductance.
D) Higher concentrations of Cl^- modulate the GABA_R single channel conductance.