Optical mapping of optically paced embryonic hearts

Area of Science:

• Developmental biology
• Cardiovascular physiology
• Biophysics

Background:

• Early embryonic heart conduction patterns are complex and rapidly changing.
• Studying embryonic heart electrophysiology is challenging due to small size and limitations of electrical pacing.
• Electrical pacing in embryonic hearts creates artifacts that hinder comprehensive recordings.

Purpose of the Study:

• To investigate optical point stimulation as a method for pacing embryonic quail hearts.
• To assess the feasibility of optical mapping for recording electrical activity in paced embryonic hearts.
• To overcome the limitations of electrical pacing in studying early cardiac electrophysiology.

Main Methods:

• Utilized a 1440-nm near-infrared diode laser for optical point stimulation.
• Employed high-resolution optical mapping with di-4-ANEPPS to record electrical activity.
• Applied cytochalasin D to facilitate recordings.
• Optimized stimulation parameters and signal processing to minimize optical artifacts.

Main Results:

• Optical point stimulation successfully paced embryonic quail hearts without electrical artifacts.
• An optical artifact due to thermal lensing was observed near the stimulation point.
• Signal processing and parameter optimization effectively minimized the optical artifact.
• Electrical activity across most of the embryonic heart surface was successfully recorded.

Conclusions:

• Optical point stimulation is a viable alternative to electrical pacing for studying embryonic heart electrophysiology.
• This technique enables detailed mapping of cardiac electrical activity in developing hearts.
• Further optimization can enhance the quality of optical mapping data in embryonic hearts.