Effects of 1 nM Aβ on α7β2-nAChRs expressed in acutely dissociated hippocampal interneurons or VTA dopamine neurons. Typical traces illustrate the effects of 1 nM scrambled Aβ (Aa) or oligomeric Aβ Ab) on 10 mM choline-induced currents recorded from hippocampal interneurons and from VTA DA neurons (Ac). The membrane potential was held at −60 mV for these recordings. B: Concentration-response profile shows that choline-induced currents in hippocampus CA1 interneurons were more sensitive to block by Aβ (at the indicated concentrations in M after pre-exposure for 2 min) than those in VTA neurons. C: Summarized results of experiments as shown in A. Each symbol was averaged from 6 cells tested. The vertical bars indicate Mean ± SE. **p < 0.01, t-test.