[Roles of ventrolateral orbital cortex in pain modulation and acupuncture analgesia].

The ventrolateral orbital cortex (VLO) is a major component of orbital cortex, which has extensive connections with periaqueductal gray (PAG), thalamus and other cortical regions. Researches suggest that the VLO is involved not only in nociception, but also in pain modulation, through activation of PAG brainstem descending antinociceptive pathway to inhibit the nociceptive inputs at the spinal/trigeminal level. Furthermore, many results demonstrate that opioid, 5-HT, GABA and their receptors are involved in the VLO antinociception. VLO plays an important role in acupuncture analgesia. In this review we summarized the roles of ventrolateral orbital cortex in pain modulation and acupuncture antinociception.