Brain Structural and Functional Alterations in Native Tibetans Living at High Altitude

Area of Science:

• Neuroscience
• Human Adaptation
• Genetics

Background:

• Tibetans exhibit remarkable adaptation to high-altitude environments.
• The specific genetic effects on the brain structure and function of Tibetans remain largely unidentified.

Purpose of the Study:

• To investigate the physiological characteristics, brain structure, and neuronal spontaneous activity in native Tibetans compared to Han immigrants at high altitude.
• To identify potential genetic influences on brain adaptations to high altitude.

Main Methods:

• Recruited 25 native Tibetans and 20 Han immigrants living in Lhasa (3650 m).
• Assessed physiological parameters (SpO2, heart rate, blood counts).
• Analyzed brain structure (gray matter volume) and neuronal activity (ALFF, VMHC, FC) using neuroimaging techniques.

Main Results:

• Tibetans displayed higher peripheral oxygen saturation (SpO2) and lower physiological markers of altitude stress (heart rate, red blood cells, hematocrit, hemoglobin) compared to Han immigrants.
• Tibetans showed increased gray matter volume in visual cortex, hippocampus, and rectus.
• Tibetans exhibited altered neuronal activity, including increased ALFF in the left putamen and left fusiform gyrus, decreased VMHC in the precentral gyrus, and reduced FC between the left precentral gyrus and other regions.

Conclusions:

• Tibetan adaptation to high altitude is associated with significant alterations in brain structure and function.
• Genetic factors likely modulate specific brain regions, as evidenced by correlations between physiological markers (hemoglobin, hematocrit, SpO2) and brain activity/connectivity.