Preoptic activation and connectivity during thermal sweating in humans.

Area of Science:

• Neuroscience
• Human Physiology
• Thermoregulation

Background:

• Animal models implicate the preoptic area in brain thermoregulation.
• Limited human data exists on the preoptic area's role in temperature control.

Purpose of the Study:

• To investigate the thermoregulatory function of the human preoptic area using functional magnetic resonance imaging (fMRI).
• To identify brain regions involved in human thermoregulation and their communication pathways during thermal stress.

Main Methods:

• Functional magnetic resonance imaging (fMRI) was employed on human volunteers subjected to whole-body heating.
• Sweating events were monitored using finger skin resistance to gauge physiological response.
• A seed-based correlation analysis was performed focusing on the preoptic area's activity.

Main Results:

• A specific cluster in the preoptic area showed activity correlated with thermal sweating.
• Increased correlation between the preoptic area and regions like the dorsal cingulate cortex and anterior insula was observed during heating.
• Enhanced communication from the preoptic area to other brain regions was evident under thermal stress.

Conclusions:

• Provides the first neuroimaging evidence for the preoptic area's thermoregulatory role in humans.
• Suggests the preoptic area integrates thermal information and signals to other brain regions for autonomic control during heat stress.