Fig. 5. Electrophysiologic properties of hypothalamic paraventricular nucleus parvocellular neurons that have I hchannels. (A ) Neuron displaying time-dependent inward rectification and lacked transient outward rectification (black arrow ) in response to a series of depolarizing current pulses delivered at a hyperpolarized membrane potential. (B ) Neuron displaying inward rectification (sag), which was blocked by 50 μm ZD7288 in response to a −60-pA hyperpolarizing current pulse. ACSF = artificial cerebrospinal fluid.