Critical period plasticity enables credit assignment.

Area of Science:

• Neuroscience
• Developmental Biology
• Computational Neuroscience

Background:

• Synaptic plasticity is crucial for learning but faces the credit assignment problem.
• Neurons need to receive instructions relevant to their specific behavioral function.

Purpose of the Study:

• Investigate a developmental mechanism for credit assignment in neural circuits.
• Understand how instructive inputs organize downstream architecture for learning expression.

Main Methods:

• Studied the olivocerebellar learning system in zebrafish during a critical developmental period.
• Combined experimental observations with mathematical theory and computational modeling.

Main Results:

• Instructive inputs from the inferior olive regulate long-range cerebellar projections.
• Developmental experience shapes projections to targets coactivated with olivary inputs.
• The resulting architecture constrains later learning, enabling credit assignment.

Conclusions:

• Instructive inputs first build the circuits they subsequently teach.
• This coordination of development and learning enables effective credit assignment.
• Protecting developmental architecture enhances learning robustness.