Figure 1.
Postsynaptic cAMP increases synaptic excitation of aCC/RP2. Ai, Whole-cell voltage-clamp recordings (Vh, -60 mV) from aCC/RP2 reveal large inward currents that are the result of the evoked release of presynaptic ACh (Baines et al., 1999, 2001). Aii, These currents are significantly increased in amplitude after overexpression of rut in aCC/RP2. Each panel shows three successive currents overlayed. Bi, The averaged amplitude of excitatory currents recorded in aCC/RP2 is significantly increased (p ≤ 0.01) after postsynaptic expression of UAS-rut compared with controls (c, parental stocks). Bii, Cumulative probability plots of individual excitatory currents reveals a clear increase in amplitude after overexpression of rut in aCC/RP2. Ci, Cii, Targeted expression of rut to cholinergic neurons (B19-GAL4) does not effect the amplitude of synaptic currents recorded in aCC/RP2. Di, Dii, In the presence of TTX (0.1 μm), evoked excitatory currents are abolished, leaving only those currents that are elicited from the spontaneous release of vesicles in the presynaptic interneurons (Dii, inset; calibration: 4 pA, 0.2 sec). Spontaneous currents in aCC/RP2 are unaffected in amplitude after overexpression of rut in these motoneurons. For all values, n > 8; mean ± SE.