Circuit Robustness to Temperature Perturbation Is Altered by Neuromodulators

Area of Science:

• Marine biology
• Neuroscience
• Crustacean physiology

Background:

• The pyloric rhythm in Cancer borealis is temperature-sensitive.
• Previous studies showed rhythm stabilization with descending modulatory inputs.
• The role of specific neuromodulators in temperature tolerance was unclear.

Purpose of the Study:

• To investigate the interaction between neuromodulators and temperature on the pyloric rhythm.
• To determine the effects of oxotremorine, proctolin, and serotonin on temperature-induced destabilization of the pyloric rhythm.
• To explore animal-to-animal variability in rhythm stability under thermal stress.

Main Methods:

• Studied temperature effects on isolated Cancer borealis preparations without descending modulatory inputs.
• Administered oxotremorine, proctolin, and serotonin to preparations under varying temperatures.
• Observed and analyzed changes in pyloric rhythm frequency and stability.

Main Results:

• In the absence of descending inputs, the pyloric rhythm was destabilized by temperature.
• Oxotremorine and proctolin increased pyloric rhythm robustness against temperature changes.
• Serotonin decreased pyloric rhythm robustness, making it more susceptible to thermal destabilization.
• Significant animal-to-animal diversity in crash stability was observed.

Conclusions:

• Neuromodulators play a critical role in maintaining pyloric rhythm stability under thermal stress.
• Oxotremorine and proctolin confer thermal resilience, while serotonin reduces it.
• Observed variability suggests underlying cryptic differences in cellular and network parameters revealed by extreme perturbations.