Excitatory and inhibitory junction potentials of circular smooth muscle cells in guinea pig ileum and colon are suppressed 30-90 minutes after setting up in vitro preparations. We have previously shown this ‘unresponsive’ period is associated with a transient loss of dye coupling between smooth muscle cells, which subsequently recovers over the ensuing 30-90 minutes; junction potentials recover in parallel with dye coupling (Carbone et al., 2012). Here, we investigated which components of dissection trigger the initial loss of coupling. Intracellular recordings were made from circular muscle cells of guinea pig ileum with micropipettes containing 5% carboxyfluorescein. After allowing 90-120 minutes for junction potentials to reach full amplitude, we re-cut all 4 edges of the preparation more than 1mm from the recording sites. This caused a reduction in the amplitude of IJPs from 17.2± 0.7mV to 9.5±1.5mV (P