Evaluate the collective function of references cited together in a given text segment.
Classify their combined role into one of the following categories: 'method', 'background', or 'result'.

Text:Indeed, although the reversal potential of GABAergic responses in mature animals varies across different neuron types (24–26) and locations (27, 28), it is generally close to the resting membrane potential, thereby having a shunting effect at rest.
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