Biomaterial Database

Nonassociative learning in the leech Hirudo medicinalis. 2001

M L Zaccardi, and G Traina, and E Cataldo, and M Brunelli

Dipartimento di Fisiologia e Biochimica G. Moruzzi, Università degli Studi di Pisa, Via S. Zeno, 31, 56127 Pisa, Italy.

In the present study we examined nonassociative learning of the induction of swimming which was evoked by weak electrical stimulation in the leech Hirudo medicinalis. The behavioural response to stimuli applied repeatedly to the body wall at an inter-trial interval (ITI) of 1 min decreased, eventually ceased, and then recovered spontaneously. More rapid reduction of the behavioural response occurred in repeated training sessions. This decrement of response conformed to the operational definition of habituation. Moreover, a noxious stimulus (i.e. brushing on the skin) facilitated the decremented response (dishabituation). In addition, we compared response decrement in naive animals with decrement in dishabituated and in sensitized animals. The analysis of the best fitting functions of the habituation, the habituation of dishabituation and the habituation of sensitization revealed interesting differences in these processes.

UI	MeSH Term	Description	Entries
D007865	Leeches	Annelids of the class Hirudinea. Some species, the bloodsuckers, may become temporarily parasitic upon animals, including man. Medicinal leeches (HIRUDO MEDICINALIS) have been used therapeutically for drawing blood since ancient times.	Hirudinea,Hirudineas,Leeche
D009043	Motor Activity	Body movements of a human or an animal as a behavioral phenomenon.	Activities, Motor,Activity, Motor,Motor Activities
D011939	Mental Recall	The process whereby a representation of past experience is elicited.	Recall, Mental
D004558	Electric Stimulation	Use of electric potential or currents to elicit biological responses.	Stimulation, Electric,Electrical Stimulation,Electric Stimulations,Electrical Stimulations,Stimulation, Electrical,Stimulations, Electric,Stimulations, Electrical
D006185	Habituation, Psychophysiologic	The disappearance of responsiveness to a repeated stimulation. It does not include drug habituation.	Habituation (Psychophysiology),Habituation, Psychophysiological,Psychophysiologic Habituation,Psychophysiological Habituation,Habituations (Psychophysiology)
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D001245	Association Learning	The principle that items experienced together enter into a connection, so that one tends to reinstate the other.	Association Learnings,Learning, Association,Learnings, Association