A) Bath application of 600 nM oxytocin failed to produce
any clear response in PVN CRH neurons voltage clamped at −50 mV.
B) For local application experiments, 1 μM oxytocin was
loaded into a glass pipette, which was connected to a picospritzer. The tip of
the pipette was then placed within ~20 um of the cell soma, and
5–10 msec puffs of oxytocin were delivered at 5 Hz every 30 seconds. The
top trace in panel B illustrates a single sweep recorded during one such
application. Each dot represents a single 10 msec puff. The bottom trace is an
average of 12 sweeps delivered at 30 second intervals from the same cell as
illustrated in the top trace. This experiment was repeated 6 times, and none of
the 6 PVN CRH neurons tested showed any rapid response to local application of
OT. Specifically, when data in each sweep was baseline subtracted to a 1.9
second period immediately before local application, mean current observed in the
6 seconds immediately after local application was identical to baseline (0.08
± 1.19 pA, n-6, p=0.7).