Fibroblast-myocyte electrotonic coupling: does it occur in native cardiac tissue?

Area of Science:

• Cardiovascular Physiology
• Cellular Electrophysiology
• Cardiac Tissue Engineering

Background:

• Heterocellular electrotonic coupling between cardiac myocytes and non-excitable connective tissue cells is well-established in vitro.
• The existence and significance of this coupling in native myocardium in vivo remain debated.
• Understanding this interaction is crucial for comprehending myocardial function and disease.

Purpose of the Study:

• To review the historical development of experimental and conceptual insights into cardiac myocyte-non-myocyte coupling in vivo.
• To present and critically evaluate evidence supporting and refuting the presence of such coupling in native myocardium.
• To identify key areas for future research to clarify the extent, regulation, and pathological relevance of this coupling.

Main Methods:

• Literature review of in vitro and in vivo studies.
• Analysis of experimental data and conceptual models.
• Synthesis of evidence from diverse research methodologies.

Main Results:

• In vitro evidence strongly supports heterocellular electrotonic coupling.
• In vivo evidence is more controversial, with ongoing debate regarding its presence and functional significance.
• Demonstrated presence of coupling in vivo is suggested, but its extent, regulation, and pathological context require further elucidation.

Conclusions:

• While in vitro coupling is confirmed, its in vivo relevance in native myocardium is still under investigation.
• Further research is essential to determine the functional extent, regulatory mechanisms, and pathophysiological impact of cardiac myocyte-non-myocyte coupling in vivo.
• Resolving this debate is critical for advancing our understanding of myocardial electrophysiology and developing targeted therapies.