Figure 1.

NRG-1β depotentiates LTP at CA1 synapses. The black bars indicate time of NRG-1 treatment. A, Basal synaptic transmission is not modified by 0.1 nm (•; n = 7) or 1.0 nm (○; n = 7) NRG-1β. B, Effects of 0.1 nm NRG-1β (•) or vehicle (○) on LTP analyzed 20 min after TBS (arrow). Values are normalized to mean fEPSP slopes recorded 10 min before TBS (n = 10). Inset, Representative fEPSPs (10 traces averaged) taken before the TBS (1), after stabilization of LTP expression (2), and after perfusion with 0.1 nm NRG-1β (3). Calibration: 5 ms, 1 mV. C, No effect on LTP expression observed with 1 nm NRG-1α isoform (▴; n = 5) or vehicle (▵; n = 5). D, PD158780 (10 μm; gray bar) blocks LTP depotentiation by NRG-1β and augments its expression (n = 7; ^*p < 0.05). Data are expressed as mean ± SEM.