BBP - MMER - Kuzirian et al - Hermissenda - [Contents]

  Species (common/scientific names): sea slug/ Hermissenda crassicornis .

Discipline(s): Neurobiology, Mariculture


The sea slug, Hermissenda crassicornis: phylogeny, mariculture, and use as a model system for neurobiological research on learning and memory.

Alan M. Kuzirian, Tom Capo, Donna McPhie, and Catherine T. Tamse

The Marine Biological Laboratory, Woods Hole, MA 02543

Abstract:
The central nervous system of this marine nudibranch mollusc provides a simple preparation, by vertebrate standards, for studying many aspects of learning and memory retention and behavioral modifications initiated by a Pavlovian training paradigm. The training paradigm consists of a unconditioned stimulus (UCS), agitation that produces a unconditioned response (UCR), foot contraction, and the conditioned stimulus (CS), light that produces the conditioned response of light-induced foot contraction and suppression of phototaxis (CR). Thus there is a response transfer where the conditioned stimulus assumes characteristics of rotation (the UCS). These demonstrable learning and memory modifications consist of measurable biophysical, biochemical and morphological changes, all of which are pairing specific induced changes. The memory changes are long lasting, and the parameters duplicate those accepted for vertebrate memory models; there are requirements for or elements of contiguity, contingency, extinction, facilitation, and habituation.

This animal, along with a few other mollusks, also has been used as a model system to study strontium's role in initiating calcification (biomineralization). This strontium dependent process is concentration dependent and temporally specific. Through the use of strontium-free seawater, ataxic animals thus produced are potentially useful for studying vestibular function under simulated conditions of weightlessness.

Feral populations naturally occurring along the Pacific Coast of North America provide a year-round supply of fecund animals. However, these populations are still subject to natural fluctuations and their availability can vary unpredictably. The risk of disease is a constant threat, especially during El Nino events. The potential biomedical use of this animal is enhanced by our ability to culture the nudibranch in the laboratory. The generation time from egg-to-egg ranges from 90-100 days. The animal's small size and eutrophic diet make them ideal for lab-culture. By such methods, healthy, rapid-growing animals, which demonstrate reduced experimental variability between animals, and in stable supplies can be produced. .


Table of Contents
Citation:
Kuzirian, A.L., T. Capo, D. McPhie, and C. T. Tamse. 1999. The sea slug, Hermissenda crassicornis: phylogeny, mariculture, and use as a model system for neurobiological research on learning and memory. Mar. Mod. Elec. Rec. [serial online] [cited {fill in: day, month, year}]. Available from http://www.mbl.edu/html/BB/MMER/KUZ/KuzTit.html