Many parasites enter their hosts by sensing signals that inform them that a host is near. Some nematode parasites are passively ingested by pigs. The infective larvae stage of the swine parasitic nematode, Oesophagostomum dentatum, exhibit behaviors that may enhance their ingestion by pigs. To investigate neuronal control ofO. dentatum's behavior, Fredrik Hoholm et al. initiated an investigation into the structure of the amphidial neurons of this parasite.

Results of their study were published in the Journal of Parasitology 2005 91: 61-68. The cover image includes an electron micrograph of a transverse section showing unexpected neural head structures from the parasite’s infective third-stage larva. The dendritic process of the finger cells in O. dentatum extends into unusual linguiform projections that, in turn, extend into the lumen of the mouth tube, an arrangement that has not been described in other nematodes.

View more micrographs and the full article here.