Personality differences affect brainstem autonomic responses to visceral pain.

Area of Science:

• Neuroscience
• Psychophysiology
• Autonomic Nervous System

Background:

• Brainstem autonomic nuclei process interoceptive signals, including pain, to regulate homeostasis and defense.
• Cardiac Vagal Control (CVC), a key psychophysiological marker, is linked to health and disease, non-invasively measured by heart rate variability.
• Understanding visceral pain response profiles is crucial for elucidating psychophysiological mechanisms.

Purpose of the Study:

• To investigate the psychophysiological response profiles to visceral pain.
• To determine the relationship between cardiac autonomic control and personality traits during visceral pain.

Main Methods:

• Electrocardiographic recordings were obtained from 19 healthy subjects during esophageal balloon distensions.
• Cardiac Vagal Control originating from the nucleus ambiguus (CVC(NA)), heart rate, and Cardiac Sympathetic Index (CSI) were analyzed.
• Psychological state and trait measures, including neuroticism and extroversion, were assessed.

Main Results:

• Subjects with increased CVC(NA) during pain exhibited higher neuroticism, anxiety, and sensory sensitivity.
• Cluster analysis revealed two distinct psychophysiological groups with contrasting baseline autonomic activity, pain tolerance, and heart rate responses.
• Group 1 (higher neuroticism, lower extroversion) showed lower baseline CVC(NA), higher heart rate and CSI, lower pain tolerance, and attenuated heart rate response to pain.

Conclusions:

• Distinct psychophysiological response profiles to visceral pain are associated with personality traits.
• These profiles may represent different active and passive defense mechanisms.
• Further research is needed to explore the clinical relevance of these endophenotypes as vulnerability factors for pain and emotion disorders.