Retained Motor Skills Linked to Single-Neuron Activity

The study covered in this summary was published bioRxiv.org as a preprint and has not yet been peer reviewed.

Key Takeaways

• Analysis of stereotyped behavior patterns with recordings of single-neuron activity in the motor cortex and dorsolateral striatum reveal that neural circuit dynamics are highly stable at the level of single neurons.

• Stable single-unit activity in motor circuits is involved in driving learned behavior.

• The small amount of drift in task-related neural activity could be due to concomitant slow drift in a behavior.

• In innate behavior, the neural correlates of behavior are also stable and are not directly dependent on motor circuits.

Why This Matters

• In a nervous system that is in constant flux, repeated motor skills are stored in motor circuits of the brain and are stably maintained and can be reliably executed, but little is known how these skills persist over time.

• This study addressed how established behavior is retained and stably produced by single-neuron activity in fixed circuits.

Study Design

• To investigate if stereotyped motor behaviors were driven by stable single-neuron dynamics, two major nodes of the motor system involved in the acquisition of motor skills, the motor cortex and dorsolateral striatum, were examined.

• Animal training and data acquisitions was done using six rats trained in an automated home-cage system on lever-pressing tasks.

• To analyze all experimental data, time-warped neural activity was done using piecewise linear warping.

• A recurrent neural network model was used to determine whether long-term single-unit recordings were needed.

Key Results

• Motor memories are retained by maintaining stable task-associated activity patterns in single neurons.

• Task-aligned activity of neurons in both the motor cortex and dorsolateral striatum were consistent over time.  

• Drift in neural activity is driven by slowly changing behavior. The drift in behavior was correlated with the recorded drift in neural activity, suggesting that neural drift could be explained by small but systematic behavioral changes.

• Observations extend to innate behavior, suggesting stable sensorimotor circuits underlie stereotyped behavior. Neural activity patterns associated with innate behavior are stable over long timescales, similar to learned motor skills.

Limitations

• Explicit limitations in the study were not discussed by the authors.

Disclosures

• The study received no commercial funding.

• None of the authors disclosed relevant financial relationships.

This is a summary of a preprint research study, “ Long-term stability of single neuron activity in the motor system ,” written by researchers at Harvard University, Department of Organismic and Evolutionary Biology and Center for Brain Science, Cambridge, Massachusetts and the University of Cambridge, Computational and Biological Learning Lab, Department of Engineering, Cambridge, England, on bioRxiv provided to you by Medscape. This study has not yet been peer reviewed. The full text of the study can be found on bioRxiv.org.

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