Specificity in neuronal network formation: Molecular mechanisms and physiopathological implications of layer- and domain-specific connectivity

The correct functioning of the nervous system is critically dependent on formation of the orderly and stereotyped patterns of neuronal network. Elucidation of molecular and cellular mechanisms of neuronal network formation is one of the major goals of neuroscience research, as it will help us understand how the nervous system perceives sensory information, conduct information processing and computation, generate appropriate behavioral responses, and perform cognitive functions. Furthermore, since deficits in neuronal network formation have been implicated in pathogenesis of complex neurological and psychiatric disorders, a better understanding of neuronal network formation will provide novel insights into pathogenesis and potential therapeutic strategies for such disorders. This Research Topic aims to bring together recent advances that elucidate the molecular, cellular, and activity-dependent processes shaping layer and domain-specific axon projections, and to examine how perturbations in these processes contribute to the development of neurological and psychiatric disorders.

Many regions of the nervous system are organized into histologically distinct layers and domains, each comprising a specific set of neuronal subtypes distinguished by their morphology, molecular signatures, and functional roles. In addition, different populations of afferent axons confine their axon terminal arbors and synapses to distinct subsets of laminae/domains in the target region. This layer/domain-specificity of axon projection is a key characteristic feature of the neuronal network, both in the vertebrate and invertebrate nervous systems. While topographic mapping has received considerable attention, the molecular and cellular mechanisms that establish layer- and domain-specific connectivity are less well studied.

This Research Topic aims to further our understanding of how layer- and domain-specificity of neuronal network is established during development and how defects in this developmental process contribute to pathogenesis of neurological and psychiatric disorders. The themes covered in this Research Topic will include, but not limited to, the following subjects:

• Anatomy of layer- or domain-organizations in the nervous system

• Axon guidance molecules and their functions in layer- or domain-specific axon projection

• Activity-dependent mechanisms of layer- or domain-specific axon projection

• Experimental approaches and models for studies of layer- or domain-specific axon projections

• Theories of layer- or domain-specific axon projection

• Neurological and psychiatric disorders that involve defects in layer- or domain-specific axon projections