Recovery from habituation in Caenorhabditis elegans is dependent on interstimulus interval and not habituation kinetics.

Abstract

The habituation of the tap withdrawal reflex of Caenorhabditis elegans was assessed to determine whether the kinetics of recovery from habituation were dependent on the interstimulus interval (ISI) used during habituation training, or alternately, on the rate and asymptotic level of habituation produced at a given ISI. Two groups of intact animals were trained at either a 10-s (CON10) or a 60-s (CON60) ISI. Laser ablation was used to alter the habituation kinetics in one further group of animals (PLM10), independent of ISI. Although the PLM10 animals trained at a 10-s ISI habituated like CON60 worms, the recovery from habituation of the PLM10 animals very closely resembled the recovery of the CON10 worms. Thus recovery kinetics are dictated by consequences of a given ISI, which do not impact upon habituation rate and asymptote. This suggests the recruitment of multiple ISI-dependent processes during habituation in C. elegans.