Figure 1.
ACh induces a Ca2+ wave and long-lasting synaptic enhancement. A, Top, Representative EPSCs (brief inward deflections) and inward current induced by ACh application. A, Middle, Representative averaged EPSCs (n = 20; as in all other cases) before (1) and during synaptic inhibition (2) and enhancement (3) induced by ACh application. A, Bottom, Time course of the EPSC amplitude (percentage) during the induction of LTPIP3 by ACh (black arrow; n = 20). B, Top, Representative CA1 pyramidal neuron loaded with fluo-3 (100 μm) and the superimposed Ca2+ signals recorded at four different sites in the dendrite (white arrows 1, 2, 3, and 4). Note that the fluorescence signal originates in the distal part of the dendrite (1) and increases as it spreads to the soma (4). Scale bar, 35 μm. B, Bottom, Averaged somatic Ca2+ signal induced by ACh and superimposed EPSCs before (Control; black trace) and after ACh (30 min after ACh as in all other figures; gray trace) showing the potentiation.