Afterhyperpolarisation current (IAHP) in immunopositive oxytocin (OT) and vasopressin (VP) neurones in slices. A, IAHP in an OT neurone produced by a train of 17, 5-ms voltage pulses (−60 mV to +10 mV) at 20 Hz. The IAHP is strongly inhibited by the PIP2 blocker, wortmannin (1 μmol L−1) (grey trace). B, In contrast, the IAHP to the same stimulus in a VP neurone is unaffected by wortmannin. In both (A) and (B), the amplitudes of voltages pulses have been truncated. Modified from Kirchner et al84