Fig. 4

Effect of manual acupuncture-like stimulation of a forepaw on extracellular ACh release in the parietal cortex in aged rats. a Diagram of the experiment demonstrating the microdialysis probe in the cerebral parietal cortex. b, c CNS-intact condition (n = 8 in 4 rats, 2 trials per rat). d, e Spinalized condition (n = 4 in 4 rats). b, d Temporal changes in ACh release in the parietal cortex ipsilateral to the stimulation site. Cortical ACh release measured every 3 min is plotted on the ordinate. Onset of the acupuncture-like stimulation is expressed as time zero on the abscissa. c, e Changes in ACh release in the parietal cortex ipsilateral (shaded column) or contralateral (hatched column) to the stimulation site during the stimulation. Each column and vertical bar shows mean ± SEM. **p < 0.01; significantly different from the pre-stimulus control value using one-way repeated-measures ANOVA, followed by Dunnett’s multiple comparison test. There were no significant differences between ipsilateral and contralateral cortical ACh release responses (c Student’s t-test, e paired t-test)