It is generally agreed that cortical processing of nociceptive stimuli is responsible for the more complex, non-reflexive, and clinically relevant aspects of pain.  Human imaging studies are demonstrating the importance of specific cortical areas in nociception, the insular cortex in particular.  Presently the neural circuits through which the cortex is involved in nociceptive processing remain largely unknown. 

We have previously identified a region within the insular cortex of the rat, the rostral agranular insular cortex (RAIC), and shown its involvement in the modulation of pain behavior through opioidergic mechanisms (Burkey et al. J Neurosci 1996 16(20):6612-23). Our most recent work (Burkey et al.  J Neurosci 1999; 19:4169-79) has demonstrated that blocking dopamine reuptake in the RAIC, which receives dense dopaminergic innervation, produces sustained behavioral antinociception and inhibition of cell activity in nociceptive areas of the spinal cord. We are currently investigating the role of GABA in RAIC antinociception. 

Anatomy of the RAIC

Our previous studies on morphine and domapine in the RAIC

Current anatomical studies on the connections between the RAIC and the ventral tegmental area (VTA)