The locus coeruleus broadcasts prediction errors across the cortex to promote sensorimotor plasticity.

Area of Science:

• Neuroscience
• Computational Neuroscience
• Systems Neuroscience

Background:

• Prediction errors, the discrepancy between expected and actual sensory input, are crucial for learning-related plasticity.
• Neuromodulatory systems, like the locus coeruleus (LC), are hypothesized to gate this plasticity by responding to prediction errors.

Purpose of the Study:

• To investigate the role of the locus coeruleus (LC) in mediating prediction error signals and facilitating sensorimotor plasticity.
• To determine if LC activity correlates with prediction errors and if stimulating LC can enhance cortical plasticity.

Main Methods:

• Two-photon calcium imaging in mice navigating a virtual environment to record LC axon activity in the cortex.
• Optogenetic stimulation of LC axons in the primary visual cortex during locomotion tasks.

Main Results:

• LC axon activity in the cortex significantly correlated with the magnitude of unsigned visuomotor prediction errors.
• LC responses were consistent across motor and visual cortical areas, suggesting widespread prediction error signaling.
• Optogenetic LC stimulation rapidly facilitated stimulus-specific suppression of visual responses, mimicking long-term visuomotor learning.

Conclusions:

• Prediction errors directly drive locus coeruleus (LC) activity.
• LC activation plays a key role in facilitating sensorimotor plasticity within the cortex.
• LC acts as a critical modulator of learning rates, accelerating the adaptation process.