Precise timing is ubiquitous, consistent, and coordinated across a comprehensive, spike-resolved flight motor...

Area of Science:

• Neuroscience
• Biophysics
• Animal Behavior

Background:

• Action potentials (spikes) convey information through their number and timing.
• Spike timing is vital in sensory systems and increasingly recognized in motor control.
• The ubiquity, consistency, and coordination of spike timing codes in motor control remain largely unexamined.

Purpose of the Study:

• To investigate the role and characteristics of spike timing codes in motor control.
• To determine how consistently spike timing is used across different motor units.
• To assess the coordination mechanisms between motor units based on spike timing and count.

Main Methods:

• Simultaneous recording of action potentials from nearly all major wing muscles of the hawk moth (Manduca sexta).
• Measurement of resulting forces during tethered flight.
• Analysis of information content in spike timing versus spike count for behavioral encoding.
• Quantification of muscle coordination using pairwise redundancy and interaction information.

Main Results:

• Spike timing, rather than spike count, provided more information about turning behavior in every motor unit.
• Each muscle consistently integrated spike timing and count information in a 3:1 ratio.
• All pairs of muscles demonstrated coordination, primarily driven by spike timing, not spike count.

Conclusions:

• Spike timing codes are ubiquitous, consistent, and essential for motor control and coordination.
• Precise millisecond-scale timing of neural signals plays a fundamental role in complex behaviors.
• The findings in Manduca sexta offer a model for understanding motor control principles in other species.