Trogocytosis: An underappreciated but vital cellular process in the nervous system

Trogocytosis is a process in which one cell nibbles part of the cellular structures of other cells, playing a crucial role in neuronal pruning and circuit formation. However, the lack of understanding of trogocytosis, especially in the field of neuroscience, poses significant challenges for data retrieval and the investigation of its underlying mechanisms. Notably, most studies related to trogocytosis have not explicitly identified the phenomena they observed as trogocytosis. We have compiled some representative research and categorized them into trogocytosis occurring in epidermal cells, retinal pigment epithelium, microglia, and oligodendrocyte precursor cells. We then discuss whether the pruning of entire synapses should be considered a type of trogocytosis and explore the molecular mechanisms that differentiate trogocytosis from phagocytosis. We anticipate that further research on trogocytosis in the nervous system will advance our understanding of neurodevelopment, motor learning, neurodegenerative diseases, and beyond.