Polymorphism of Merkel cells from slowly adapting type I mechanoreceptors in the buccal pouch of the golden hamster

The shape of Merkel cells from Merkel cell-neurite complexes, which are slo wly adapting type I (SAI) mechanoreceptors in the touch dome of 3-12 week o ld golden hamster cheek pouch mucosa, were examined by immunohistochemistry and under an electron microscope. This is the first report of its kind obs erving the shapes of Merkel cells which had beforehand been established fun ctionally as SAI mechanoreceptors. Immunohistochemistry using anticytokerat in 20 antibody and light microscopic observations of quinacrine fluorescenc e treated Merkel domes revealed that some Merkel cells were of dendritic sh ape. On the other hand, many Merkel cells were of globular and/or roundish shape. Observation of Merkel cells using an electron microscope also reveal ed some dendritic-shaped Merkel cells, however almost all of them contacted nerve terminals. Tn spite of the Merkel cells shape, it seems appropriate to theorize that the majority of Merkel cells (including dendritic-shaped M erkel cells) from Merkel cell-neurite complexes in SAI mechanoreceptores ar e related to the reception of mechanical stimulation.