Excitable behavior can explain the "ping-pong" mode of communication between cells using the same chemoattractant

Area of Science:

• Cellular communication
• Mycology
• Systems biology

Background:

• Filamentous fungi like Neurospora crassa exhibit cell fusion through directed growth.
• This process involves a chemoattractant-receptor system and a "ping-pong" pulsatile communication mechanism.
• Understanding this communication is crucial for explaining cell-cell interactions in genetically identical organisms.

Purpose of the Study:

• To elucidate the paradox of how a single chemoattractant-receptor system facilitates communication without self-excitation.
• To model and understand the "ping-pong" pulsatile communication in Neurospora crassa.
• To identify the underlying principles governing stable oscillatory patterns in excitable systems.

Main Methods:

• Utilized a generic activator-inhibitor model for excitable behavior.
• Simulated pulse exchange between two interacting excitable systems.
• Analyzed the role of excitability threshold and refractory periods in communication dynamics.

Main Results:

• Demonstrated that pulse exchange leads to a stable oscillatory pattern of mutual excitation.
• Showed that excitability threshold and refractory periods explain the sudden onset of oscillations and absence of self-excitation.
• The model successfully replicates key puzzling properties of the "ping-pong" communication.

Conclusions:

• The "ping-pong" communication in Neurospora crassa is explained by two excitable systems locked in mutual oscillation.
• Excitability threshold and refractory periods are key to preventing self-excitation and enabling stable communication.
• The findings provide insights into potential molecular mechanisms underlying this fungal communication system.