(A) Biophysical properties of upper and lower L5 pyramidal neurons in anesthetized mice. Example upper (left) and lower (right) L5 neurons in response to current injections. Note the pronounced sag in the hyperpolarizing response to negative current injection in the lower L5 neuron. Scale bars, 10 mV, 200 ms.
(B) Sag ratios are larger in lower versus upper L5 neurons (black points, mean ± SEM).
(C) Example depolarized neuron exhibiting a sharp increase in Vm at the beginning of the task. Arrow indicates −50 mV.
(D) Example hyperpolarized neuron exhibiting a sharp decrease in Vm at the beginning of the task.
(E and F) Neurons depolarized during delays to reward had lower pre-task Vm and firing rates than those hyperpolarized during delays to reward (black points, mean ± SEM).