Chemical sympathectomy suppressed GHS and nerve growth factor (NGF) expression in the gastric fundus. A: graphs showing the visceromotor response to gastric distention (electromyographic activity in volts × s) as a function of distention pressure in GHS rats, before and after 6-OHDA treatment (*P < 0.01). B: after adrenalectomy (ADx). C: after sham surgery (each comparison in A, B, and C used t-test, n = 8 for each group). D: panels and bar graph illustrating the results of Western blotting measuring NGF in the fundus muscularis externa normalized to β-actin. The significant increase in NGF in GHS rats was normalized by 6-OHDA treatment but not by ADx (*P < 0.05, n = 8; ANOVA). Ctr, control. E: bar graph showing that 6-OHDA treatment almost completely ablated the expression of tyrosine hydroxylase (TH) in the gastric fundus muscularis externa while ADx had no significant effect (*P < 0.05, n = 8; ANOVA). F: bar graph showing a significant increase in the ratio of sympathetic to vagal activity in GHS rats compared with controls rats (*P < 0.05, n = 12 each; t-test).