High-resolution Optical Mapping of the Mouse Sino-atrial Node

Area of Science:

• Cardiovascular Physiology
• Cardiac Electrophysiology
• Molecular Cardiology

Background:

• Sino-atrial node (SAN) dysfunction is a significant cause of cardiac morbidity.
• Understanding SAN physiology and pathophysiology is crucial for developing new treatments.
• The mouse SAN is a valuable model for studying cardiac pacemaking due to genetic manipulability and structural similarities to larger mammals.

Purpose of the Study:

• To provide a detailed protocol for optical mapping of the mouse SAN.
• To enhance the understanding of SAN excitation and conduction mechanisms.
• To aid in the development of therapies for SAN dysfunction.

Main Methods:

• Optical mapping of the mouse SAN in intact, Langendorff-perfused hearts.
• Optical mapping of the mouse SAN in isolated atrial preparations.
• Utilizing electrophysiological and histological data to validate mouse SAN models.

Main Results:

• Optical mapping effectively visualizes excitation origin and conduction pathways within and from the mouse SAN.
• Demonstrated the representativeness of mouse SAN structure and function to larger mammals.
• Highlighted the presence of specialized conduction pathways and pacemaker hierarchy within the mouse SAN.

Conclusions:

• Optical mapping is a powerful technique for investigating mouse SAN physiology and pathophysiology.
• This protocol serves as a valuable tool for researchers studying cardiac pacemaking.
• Improved understanding of SAN function can benefit clinical treatments for SAN dysfunction.