Leptin modulates fast synaptic transmission in dog pancreatic ganglia

The aim of this study was to determine whether leptin modulates neuronal ac tivity in intrapancreatic ganglion neurons. Intracellular recordings were m ade in dog pancreatic neurons. Recombinant mouse leptin (313 nM) was added by superfusion. When leptin was present, fast EPSPs which were subthreshold in normal Krebs solution reached threshold for firing action potentials. H owever, leptin had no significant (P > 0.05, n = 18) effect on either the r esting membrane potential or on membrane input resistance. To determine whe ther leptin increased the postsynaptic sensitivity to acetylcholine, the re sponse was tested by pressure ejection of acetylcholine. Acetylcholine evok ed a 9.4 +/- 2.2 mV (mean +/- SEM, n = 5) depolarization in normal Krebs so lution. In the presence of leptin, the response was not significantly diffe rent (9.6 +/- 2.4 mV, P > 0.05). The results suggest that leptin modulates fast synaptic transmission in pancreatic ganglion neurons by acting on pres ynaptic nerve terminals. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.