Neuromodulator-induced temperature robustness in a motor pattern: a comparative study between two decapod...

Area of Science:

• Neuroscience
• Crustacean physiology
• Environmental adaptation

Background:

• Temperature fluctuations challenge nervous system function, especially in poikilothermic (cold-blooded) animals.
• Neuronal systems must maintain function across a wide thermal range.
• Previous work identified neuropeptide modulation as a thermal protection mechanism in Jonah crabs.

Purpose of the Study:

• To investigate if neuropeptide modulation enhances temperature robustness in Dungeness and green crabs.
• To determine if the mechanisms observed in Jonah crabs are conserved across related species.
• To explore the cellular basis of neuropeptide-mediated thermal compensation.

Main Methods:

• Electrophysiological recordings of the lateral gastric neuron in Dungeness and green crabs.
• Analysis of the gastric mill pattern generator's rhythmic activity at varying temperatures.
• Manipulation of neuronal activity and neuropeptide signaling.
• Application of dynamic clamp to alter neuronal input resistance.

Main Results:

• Elevated temperatures increased leak conductance and disrupted gastric mill rhythms in both crab species.
• Increased descending modulatory input or neuropeptide application rescued rhythmic activity at higher temperatures.
• Reducing input resistance via dynamic clamp partially restored rhythmicity, suggesting distinct compensation mechanisms.

Conclusions:

• Neuropeptide modulation confers temperature robustness in Dungeness and green crabs, similar to Jonah crabs.
• Neuropeptide-mediated thermal compensation is a conserved trait across these crab species.
• The specific cellular mechanisms underlying this compensation may differ between species.