Thermosensory activation of insular cortex.

Area of Science:

• Neuroscience
• Sensory Processing
• Pain Perception

Background:

• Temperature sensation is traditionally linked to the somatosensory cortex.
• Emerging evidence points to the insular cortex's role in processing thermal information.
• The insular cortex is implicated in interoception and limbic functions.

Purpose of the Study:

• To investigate the brain regions involved in human temperature sensation.
• To explore the relationship between insular cortex activity and thermal perception.
• To examine the potential role of the insular cortex in central pain syndrome.

Main Methods:

• Positron emission tomography (PET) was used to measure brain activity.
• Participants were exposed to graded cooling stimuli.
• Brain activity was correlated with the intensity of perceived cold.

Main Results:

• Contralateral activation in the dorsal middle/posterior insula correlated with cooling stimuli.
• This region aligns with the primate lamina I spinothalamic pathway.
• Activation in the right anterior insula and orbitofrontal cortex correlated with perceived thermal intensity.

Conclusions:

• The dorsal insula is a key area for human thermoreception, part of a limbic sensory pathway.
• Findings support the hypothesis that central pain after stroke may result from impaired cold-induced pain inhibition in the insula.
• Anterior insula and orbitofrontal cortex activity reflects the subjective experience of thermal intensity.