The molecular signals that regulate activity-dependent synapse refinement in the brain

The formation of appropriate synaptic connections is critical for the proper functioning of the brain. Early in development, neurons form a surplus of immature synapses. To establish efficient, functional neural networks, neurons selectively stabilize active synapses and eliminate less active ones. This process is known as activity-dependent synapse refinement. Defects in this process have been implicated in neuropsychiatric disorders such as schizophrenia and autism. Here we review the manner and mechanisms by which synapse elimination is regulated through activity-dependent competition. We propose a theoretical framework for the molecular mechanisms of synapse refinement, in which three types of signals regulate the refinement. We then describe the identity of these signals and discuss how multiple molecular signals interact to achieve appropriate synapse refinement in the brain.

Automated summary

The formation of appropriate synaptic connections is crucial for the proper functioning of the brain. This process involves the selective stabilization of active synapses and the elimination of less active synapses, known as activity-dependent synapse refinement. Defects in this process are associated with neuropsychiatric disorders. This review discusses the regulation and mechanisms of synapse elimination through activity-dependent competition and proposes a theoretical framework for the molecular mechanisms involved.