Baroreceptor reflex dysfunction in the BACHD mouse model of Huntington's disease

Area of Science:

• Neuroscience
• Cardiovascular Science
• Genetics

Background:

• Huntington's disease (HD) is a neurodegenerative disorder impacting movement, emotion, and cognition.
• Autonomic nervous system (ANS) dysfunction is increasingly recognized in HD patients, potentially increasing cardiovascular event risk.
• The BACHD mouse model recapitulates key features of Huntington's disease.

Purpose of the Study:

• To investigate autonomic and cardiovascular function in the BACHD mouse model of Huntington's disease.
• To assess baroreceptor reflex sensitivity and blood pressure regulation in BACHD mice.
• To examine cardiac structural and functional changes associated with autonomic dysfunction in HD.

Main Methods:

• Baroreceptor reflex sensitivity was measured in BACHD and wild-type (WT) mice.
• Daytime blood pressure was monitored in both groups.
• Cardiac structure was assessed by heart weight to tibia length ratios.
• Echocardiography was used to evaluate cardiac function.

Main Results:

• BACHD mice exhibited a blunted baroreceptor reflex response compared to WT controls.
• Significantly higher daytime blood pressure was observed in BACHD mice.
• Increased heart weight to tibia length ratios were found in BACHD mice at 7 and 12 months of age, suggesting cardiac hypertrophy.
• Echocardiographic analysis revealed normal heart function in BACHD mice despite structural changes.

Conclusions:

• The BACHD mouse model displays significant autonomic dysfunction, characterized by impaired baroreceptor reflex and hypertension.
• Cardiac structural changes, likely a response to elevated blood pressure, are present in BACHD mice.
• These findings highlight the importance of studying autonomic and cardiovascular function in HD pathophysiology and may inform future therapeutic strategies.