More evidence for the neural specificity of particular acupuncture points comes from a Chinese study that used fMRI to investigate the effects of acupuncture at Neiguan P-6. fMRI was performed on the brains of 36 healthy subjects while they received acupuncture at Neiguan P-6 and two control points (Daling P-7 and Guangming GB-37). Needling at Neiguan P-6 caused extensive signal decreases (deactivations) in cerebrocerebellar and subcortical areas, whereas needling at GB-37 induced widespread signal increases (activations). The deactivations persisted for a prolonged time following the end of needle stimulation. In addition, acupuncture at Neiguan P-6 (unlike stimulation at Daling P-7 and Guangming GB-37) selectively evoked neural responses in the insula, hypothalamus and cerebellum. Interestingly, these brain areas are associated with the autonomic regulation of the vestibular system, which contributes to the sense of balance. Since disturbance of vestibular function leads to motion sickness, which is characterised by vertigo, nausea and vomiting, this may help explain the anti-emetic effect of Neiguan P-6. (Neural specificity of acupuncture stimulation at pericardium 6: evidence from an FMRI study. J Magn Reson Imaging. 2010 Jan;31(1):71-7).