Related Experiment Videos
Human forebrain activation by visceral stimuli.
A B King1, R S Menon, V Hachinski
1Neuroscience Program, University of Western Ontario, London, Ontario, Canada, N6A 5C1.
The Journal of Comparative Neurology
|September 25, 1999
Summary
This study used functional magnetic resonance imaging (fMRI) to map brain regions controlling visceral functions. Researchers identified specific brain areas, including the insular cortex, activated by heart rate and blood pressure changes.
Area of Science:
- Neuroscience
- Physiology
Background:
- Visceral functions are vital for survival, but the specific human brain regions controlling them remain largely unmapped.
- Previous research in animals and observations from cardiac events suggested localized brain control, but direct human evidence was lacking.
Purpose of the Study:
- To identify and map discrete human brain regions involved in visceral control using functional magnetic resonance imaging (fMRI).
- To differentiate between general visceral (cardiopulmonary) and special visceral (gustatory) control centers in the brain.
Main Methods:
- Utilized 4-Tesla fMRI to measure brain activity in five male subjects.
- Subjects underwent physiological challenges: maximal inspiration (MX), Valsalva's maneuver (VM), and isometric handgrip (HG) to alter heart rate and blood pressure.
- Gustatory stimuli (saline and sucrose) were administered to differentiate taste-related visceral areas.
Main Results:
- Increased neuronal activity was observed in the insular cortex, posterior thalamus, and medial prefrontal cortex during cardiopulmonary challenges (MX, VM, HG).
- Gustatory stimulation activated the ventral insular cortex at a distinct, more inferior location compared to cardiopulmonary stimuli.
- This study provides the first fMRI evidence of human brain activity in response to visceral stimulation.
Conclusions:
- The insular cortex, posterior thalamus, and medial prefrontal cortex are key human brain regions involved in regulating general visceral functions.
- Specific subregions within the insular cortex are dedicated to processing different types of visceral information, such as taste versus cardiopulmonary.
- This research charts previously unmapped visceral control centers in the human brain, advancing our understanding of autonomic nervous system regulation.