[Changes in functional motor asymmetry during aging and after irradiation]

Area of Science:

• Neuroscience
• Gerontology
• Radiation Biology

Background:

• Functional motor asymmetry is a key indicator of brain lateralization and neurological health.
• Aging naturally influences motor control and cognitive functions.
• Cranial irradiation can induce significant neurological damage and alter brain function.

Purpose of the Study:

• To investigate the impact of natural aging and cranial irradiation on functional motor asymmetry in female CBA mice.
• To determine if irradiation alters the age-related trajectory of motor asymmetry.
• To explore the underlying mechanisms of radiation-induced behavioral changes in the brain.

Main Methods:

• Assessment of functional motor asymmetry using a T-shaped maze behavioral test.
• Quantification of turning preference (right vs. left turns) in mice.
• Calculation of an asymmetry index for both intact and irradiated mouse populations.
• Comparative analysis of asymmetry-age relationships across different experimental groups.

Main Results:

• Both intact and irradiated mice exhibited a similar pattern in the asymmetry-age relationship, peaking between 13-17 months.
• Control mice showed a predominance of right turns, indicating typical functional motor asymmetry.
• Irradiated mice displayed a significant inversion, with a specific preference for left turns.
• This behavioral shift in irradiated mice suggests a heightened sensitivity of the dominant left hemisphere to radiation damage.

Conclusions:

• Cranial irradiation at 10 Gy induces a distinct behavioral inversion in functional motor asymmetry in aging mice.
• The dominant hemisphere appears more vulnerable to radiation-induced neurological disturbances.
• Findings suggest differential aging rates between brain hemispheres may be influenced by external factors like irradiation.