Impaired motor function in senescence-accelerated mouse prone 1 (SAMP1)

Area of Science:

• Gerontology
• Neuroscience
• Animal Models

Background:

• Senescence-Accelerated Mouse Prone (SAMP) strains display accelerated aging.
• SAMP6 and SAMP8 are established models for central nervous system alterations.
• The SAMP1/Sku (SAMP1) strain's brain alterations and behavioral dysfunction remain unclear.

Purpose of the Study:

• To investigate brain alterations and behavioral dysfunction in the SAMP1 mouse model.
• To assess motor coordination and activity levels in SAMP1 mice compared to controls.

Main Methods:

• Behavioral tests including locomotor activity, Y-maze, rotating rod, hind-limb extension, and traction.
• Histochemistry and Western blot analyses were performed.
• Evaluated 2- and 4-month-old SAMP1 and age-matched senescence-accelerated mouse resistant 1 (SAMR1) mice.

Main Results:

• 4-month-old SAMP1 mice showed reduced locomotor activity and Y-maze performance compared to SAMR1.
• SAMP1 mice at both 2 and 4 months exhibited motor-coordination dysfunction in the rotating rod test.
• Abnormal hind-limb extension reflexes were observed in 2- and 4-month-old SAMP1 mice.
• Cerebellar Purkinje cells in 4-month-old SAMP1 mice showed persistent tyrosine hydroxylase expression.

Conclusions:

• SAMP1 mice display age-dependent motor dysfunction and altered activity.
• The SAMP1 strain is a suitable model for investigating the mechanisms of motor dysfunction.
• Persistent tyrosine hydroxylase expression in cerebellar Purkinje cells may indicate underlying neuropathology.