Electrophysiological activity during recovery from anhydrobiosis in fourthstage juveniles of Ditylenchus dipsaci

Upon immersion in water, anhydrobiotic nematodes display a period of appare nt inactivity, the lag phase, before they commence spontaneous movement. Fo llowing a period of desiccation of the fourth stage juveniles of the plant- parasitic nematode Ditylenchus dipsaci, electrical activity during rehydrat ion was recorded using glass microelectrodes inserted into individual nemat odes. The pattern observed was a period of no electrical activity, followed by low amplitude electrical events and then also high amplitude events. Mo vement of the nematode was associated with the high amplitude events, whose recordings formed trains of spikes that coincided with the activity of the nematode. The lag phase represents a period during which the physiological functions of the nerves and muscles are restored. This may involve the res toration of ionic gradients between the inside and the outside of the cells , which is reflected in an increase in spike amplitude in those nematodes w here a sustained period of high amplitude activity was recorded.