Subcortical structures involved in pain processing: evidence from single-trial fMRI.

Area of Science:

• Neuroscience
• Pain Research
• Neuroimaging

Background:

• Pain perception involves both cortical and subcortical brain areas.
• Subcortical structures play roles in motor control, autonomic responses, emotion, and learning related to pain.
• The extent of nociceptive information processing in subcortical regions remains incompletely understood.

Purpose of the Study:

• To identify subcortical brain regions activated by painful stimuli using functional magnetic resonance imaging (fMRI).
• To investigate whether nociceptive information is processed asymmetrically in subcortical structures based on stimulation laterality.

Main Methods:

• Employed single-trial functional magnetic resonance imaging (fMRI) in healthy volunteers.
• Utilized Thulium-YAG laser stimuli to evoke pain without tactile sensation on either hand.
• Analyzed fMRI data for differential responses to right- versus left-sided painful stimuli.

Main Results:

• Activated subcortical regions included the hippocampal complex, amygdala, red nucleus, brainstem, and cerebellum.
• Affective pain processing structures (hippocampus, amygdala) showed bilateral activation.
• Motor control structures (red nucleus, putamen, cerebellum) exhibited asymmetric activation based on stimulus side.

Conclusions:

• Subcortical structures are significantly involved in processing nociceptive information.
• Asymmetric activation in motor-related subcortical areas suggests spatial encoding of pain for defensive responses.
• Findings highlight the role of subcortical networks in modulating pain perception and behavior.