Biophysical properties in mitral cells compared across genotype.

* = Significantly-different mean values via a Student's t-test, α ≤0.05. τInact = the inactivation time constant, τDeact = the deactivation time constant, RMP = resting membrane potential, spike frequency = calculated throughout step depolarization, intraburst frequency = calculated during spike cluster, ISI = interspike interval within a spike cluster, action potential cluster = defined as three or more action potentials with less than 100 ms pause duration, burst length = duration of the cluster, pause duration = duration between clusters, 1/e = action potential decay time. Voltage-activated currents were measured using a Vh = -80 mV with a depolarizing Vc = +40 mV of 400 ms in duration and an interpulse interval of 30–45 s. In voltage-clamp recordings in which tetrodotoxin was not applied, a sustained/transient ratio was determined when spiking prevented subsequent kinetic analysis. In current-clamp recordings, firing properties were determined using a 100 pA current injection of 4000 ms in duration. Action potential properties were determined using a 50 pA current injection of 1000 ms in duration with a 50 µs sampling frequency.