Biomaterial Database

Quantitative analysis of the relation between gill amplitude and siphon duration in the defensive withdrawal reflex of Aplysia. 1987

M Stopfer, and T J Carew

The defensive withdrawal reflex of the mantle organs (gill, siphon, and mantle shelf) of the marine mollusc Aplysia californica has been the subject of numerous studies investigating the cellular and molecular mechanisms of learning. In behavioral experiments, the reflex has been monitored by means of two different response measures, either siphon duration (in unrestrained, freely moving animals) or gill amplitude (in restrained preparations). It has generally been assumed that one component of the reflex provides a reliable index of the other. In the present study, we directly tested this assumption by simultaneously measuring both response parameters in the same experiment. Reflex response magnitude was varied in two ways: (a) by systematically varying stimulus intensity, and (b) by holding the stimulus intensity constant, but delivering stimuli at a rate that produced significant habituation. Using both measures we found that gill amplitude and siphon duration were highly correlated (average correlation = .90). Thus our data show that either response measure can serve as a reliable estimate of the overall reflex response.

UI	MeSH Term	Description	Entries
D009415	Nerve Net	A meshlike structure composed of interconnecting nerve cells that are separated at the synaptic junction or joined to one another by cytoplasmic processes. In invertebrates, for example, the nerve net allows nerve impulses to spread over a wide area of the net because synapses can pass information in any direction.	Neural Networks (Anatomic),Nerve Nets,Net, Nerve,Nets, Nerve,Network, Neural (Anatomic),Networks, Neural (Anatomic),Neural Network (Anatomic)
D012018	Reflex	An involuntary movement or exercise of function in a part, excited in response to a stimulus applied to the periphery and transmitted to the brain or spinal cord.
D005880	Gills	Paired respiratory organs of fishes and some amphibians that are analogous to lungs. They are richly supplied with blood vessels by which oxygen and carbon dioxide are exchanged directly with the environment.	Gill
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
D001048	Aplysia	An opisthobranch mollusk of the order Anaspidea. It is used frequently in studies of nervous system development because of its large identifiable neurons. Aplysiatoxin and its derivatives are not biosynthesized by Aplysia, but acquired by ingestion of Lyngbya (seaweed) species.	Aplysias
D001143	Arousal	Cortical vigilance or readiness of tone, presumed to be in response to sensory stimulation via the reticular activating system.	Vigilance, Cortical,Arousals,Cortical Vigilance
D001362	Avoidance Learning	A response to a cue that is instrumental in avoiding a noxious experience.	Aversion Behavior,Aversion Learning,Aversive Behavior,Aversive Learning,Avoidance Behavior,Aversion Behaviors,Aversive Behaviors,Avoidance Behaviors,Behavior, Aversion,Behavior, Aversive,Behavior, Avoidance,Behaviors, Aversion,Behaviors, Aversive,Behaviors, Avoidance,Learning, Aversion,Learning, Aversive,Learning, Avoidance