Leg position learning by an insect: II. Motor strategies underlying learned leg extension

Area of Science:

• Neuroscience
• Animal Behavior
• Locust Motor Control

Background:

• Learned motor behaviors are crucial for adaptation.
• Understanding the neural basis of learned movements in invertebrates provides insights into fundamental principles of motor control.
• Locust tibial extension is a well-studied model for motor learning.

Purpose of the Study:

• To investigate the myographic activity patterns associated with learned tibial extension in locusts.
• To identify and characterize distinct motor strategies employed during this learned behavior.
• To explore the neuronal mechanisms underlying these motor strategies.

Main Methods:

• Electromyography (EMG) was used to record activity in flexor and extensor tibiae muscles.
• Behavioral analysis assessed learning criteria and joint angle requirements.
• Comparison of motor strategies based on myographic and behavioral data.

Main Results:

• Three distinct motor strategies were identified: repeated flexion-extension movements, changes in muscle tonus, and tonic activity in the extensor tibiae (SETi) motoneuron.
• These strategies were selectively utilized based on the required joint angle.
• Effectiveness of each strategy was evaluated using behavioral criteria.

Conclusions:

• Locusts employ a repertoire of motor strategies for learned tibial extension.
• The selection of these strategies is dependent on the specific motor task demands (joint angle).
• The findings offer insights into the neural control and adaptability of learned movements.