Activation of the insular and opercular regions of the monkey by drinking as revealed by positron emission tomography

We measured the regional cerebral blood flow (rCBF) of the monkey using pos itron emission tomography (PET) in the following conditions: self-initiated (SELF), visually-initiated (VISUAL), and color-discriminating go/no-go (GO NOGO) hand movement tasks with reward of water, free reward condition (REWA RD), and resting states (REST). The insulae, frontal opercula, and mouth se nsorimotor area were activated in any of SELF, VISUAL, GONOGO, and REWARD, when compared with REST. These findings suggest that the insular and opercu lar regions play an important role in the neural processes involved in drin king. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.