Simple techniques suitable for student use to record action potentials from the frog heart.

Area of Science:

• Physiology
• Neuroscience
• Biomedical Engineering

Background:

• Demonstrating action potentials is crucial for science education.
• Traditional methods using skeletal muscle and glass microelectrodes face challenges with stability due to muscle contraction.
• A need exists for a more robust and accessible recording technique for physiological experiments.

Purpose of the Study:

• To present a simplified and stable method for recording action potentials in bullfrog hearts.
• To overcome the limitations of conventional intracellular recording techniques.
• To provide an accessible experimental method for educational purposes.

Main Methods:

• Utilized a flexible polyethylene electrode with a wide orifice (approx. 1 mm) for recording.
• Applied the electrode to a spontaneously beating bullfrog heart.
• Achieved extracellular recordings (electrocardiogram) and intracellular recordings (whole-cell configuration) via negative pressure.
• Secured the electrode using suction to prevent dislodgement during cardiac contraction.

Main Results:

• The polyethylene electrode provided stable recordings of action potentials from the bullfrog heart.
• The electrode remained attached and functional despite cardiac contractions.
• The method allowed for easy perfusion of the heart for further experimental manipulations.

Conclusions:

• The presented technique offers a simple, stable, and convenient approach for recording action potentials in educational settings.
• This method enhances the ability to demonstrate physiological concepts related to cardiac function and electrophysiology.
• The technique facilitates experiments investigating the effects of ionic changes and drugs on cardiac activity.