Ett par studier om Merkel celler som reagerer på vibrasjon med lav frekvens (5-30 Hz) som sier mange ting om deres funksjon. Den sier bl.a. at de utløser glutamate, som er et nevropeptid relatert til smertetilstander. Men den utløser også andre nevrotransmittere som nedregulerer andre sanse-nevroner. Pluss at den innerverer eptielceller.
http://m.pnas.org/content/101/40/14503.full

«These data indicate that Merkel cells are poised to release glutamate and neuropeptides.»

«Because the question of whether Merkel cells are sensory cells is unresolved, other functions have been proposed. For example, Merkel cells may play a passive role in touch by efficiently transmitting force to mechanosensitive afferents (12). Alternatively, they may release neuromodulators to regulate the sensitivity of mechanoreceptive neurons (20). Merkel cells have also been proposed to influence the development or innervation of epithelia (ref. 21, but see ref. 22).»

«Together, these data demonstrate that Merkel cells are excitable cells and designate glutamate and CCK8 as candidate neurotransmitters at synapses between Merkel cells and sensory afferents in vivo. Our conclusion that Merkel cells function as excitable cells is strengthened by the abundance of neuronal transcription factors that we found to be enriched in Merkel cells (Table 1).»

«How might neurotransmitter release be stimulated from Merkel cells? Merkel cells may be mechanoreceptive cells that are directly activated by touch. Alternatively, Merkel cells may receive input from active afferent terminals. The latter conjecture is bolstered by reports of reciprocal connections in Merkel cell-neurite complexes (11).»