Figure 4.

Method for estimation of synaptic reversal potential during Up states. A, Single neurons are progressively moved through a series of holding potentials at which many successive Up states are recorded (single trial current; top arrow) and aligned to the starts of Up states to produce the average Up state evoked current (average current; bottom arrow) for each holding potential. B, Current–voltage plots across the range of holding potentials are constructed for both Down state (black dashed line) and for each point during the Up state (e.g., 400 ms after Up start; gray dashed line). The intersection point of the two I–V plots represents the reversal potential for the Up state at that particular time.