Control of cricket stridulation by a command neuron: efficacy depends on the behavioral state

Area of Science:

• Neuroethology
• Acoustic Communication
• Insect Behavior

Background:

• Crickets produce distinct songs for communication using thoracic ganglia.
• Brain activity controls these stridulatory patterns, particularly calling songs.
• Descending neural pathways mediate this brain-to-thorax control.

Purpose of the Study:

• Identify the specific brain neuron controlling cricket stridulation.
• Analyze the role of this neuron in generating calling songs.
• Investigate how external stimuli, like wind, affect stridulation and neural control.

Main Methods:

• Intracellular recordings from brain neurons in crickets.
• Staining techniques to visualize neural pathways.
• Electrophysiological analysis of neural activity during stridulation and wind stimulation.

Main Results:

• A single descending interneuron identified as a command neuron for calling song.
• Depolarization of this neuron reliably elicits stridulation, correlating with chirp rate.
• Wind stimulation disrupts song but does not alter command neuron activity, indicating indirect suppression.

Conclusions:

• A specific brain interneuron acts as a command neuron for cricket calling song.
• This neuron's activity is crucial for initiating and maintaining stridulation.
• External stimuli can suppress stridulation by acting on downstream targets, not the command neuron itself.