Connections between nerve endings and epidermal cells: are they synapses?
Based on electron microscopy and confocal scanning microscopy, contacts between sensory axons and the cells of the epidermis have been described: with keratinocytes, Langerhans cells, melanocytes and Merkel cells. We would like to initiate a debate on this question: "Are neuro-epidermal connections synapses?" Anatomically, neuro-epidermal junctions can be considered as synapses in our opinion. If neuro-epidermal junctions are synapses, they probably belong to the family of en passant synapses, with nerve endings passing along epidermal cells and occasionally connecting to them. In conclusion, we suggest that neuro-epidermal junctions could be considered as true synapses, but this does not exclude non synaptic interactions.
Yannick
Y
Chateau
Laurent
L
Misery
D000818:Animals; D002478:Cells, Cultured; D004817:Epidermis / Q000294:innervation*; D015603:Keratinocytes / Q000648:ultrastructure*; D018625:Microscopy, Atomic Force; D009411:Nerve Endings / Q000648:ultrastructure*; D012867:Skin / Q000294:innervation*; D013569:Synapses / Q000648:ultrastructure*