Spatiotemporal Dynamics of Sensory Neuron and Merkel-Cell Remodeling During Epidermal Homeostasis

The study "Spatiotemporal dynamics of sensory neuron and Merkel-cell remodeling are decoupled during epidermal homeostasis" investigates the remodeling of sensory neurons and Merkel cells during normal tissue homeostasis. The researchers found that sensory axon terminals are highly dynamic, with 89% remodeling events, compared to Merkel cells with 63% remodeling events. The study also found that Merkel-cell numbers decline significantly over a month in adult mice, with 7% of all Merkel cells appearing to be added and 9% relocated within the cluster. The researchers discovered two distinct populations of Merkel cells with different lifetimes and that the plasticity of Merkel cells, but not axonal remodeling, is synchronized to the rapid epithelial regeneration that occurs during hair growth. The study also found that the presence of Merkel cells suppresses branching and promotes structural maturation. The research suggests that the rate of axonal remodeling could be set intrinsically by neuronal mechanisms or modulated by other cell types. The study raises questions about the mechanisms that dictate remodeling sensory axons during epithelial homeostasis.