ALSO IN THIS ISSUE
Evolution Of Mechanisms Of Learning And Memory In A "Model Lineage": Research In The Laboratory Of
William G. Wright
WHO WE ARE
"The Man Behind the Seaweed"
Cold Spring Harbor Laboratory Aplysia Meeting A Success
PERSONAL HYGIENE FOR SLUGSDr. Michael Schmale
Associate Professor of Marine Biology and Fisheries
Rosenstiel School of Marine & Atmospheric Science
An important component of the behind the scenes monitoring in the Aplysia culture facility is assurance of animal health. Although not generally discussed in polite company, diseases are a major dilemma for production of virtually all aquatic organisms raised in intensive culture. The key to good health in aquaculture is usually 95% good animal husbandry, 4% diligent monitoring for appearance of disease and less than 1% actual treatment of diseases. This brings us to personal hygiene. The slugs you hold dear (and pay dearly for) are not by nature easy animals to maintain in good health in intensive culture operations. Let's face it, the vast amounts of algae a slug eats (i.e., "through-put") combined with their endearing tendency to produce slime by the bucket leads to a challenging hygiene situation. After years of trial by slime, hatchery manager Tom Capo has devised a fine system for maintaining a high level of personal hygiene among the slugs at all stages of life, from egg to veliger to juvenile to adult. This system is based on provision of large volumes of clean, tropical seawater which is chilled to the cool temperatures (13-15 °C) preferred by Aplysia californica. Animals are held in flow-through cages which are disinfected weekly. Combined with a nutritious diet (see Slime Lines II) and appropriate stocking densities, these procedures result in rapidly growing, healthy animals.Please turn to page 2-->
We have investigated two forms of neuromodulation, spike broadening and increased excitability, in a clade of opisthobranch mollusks related to Aplysia. In the sensory neurons of Aplysia , spike broadening (an increase in action potential duration) and increased excitability are produced both by application of noxious stimuli and by application of the neuromodulatory transmitter serotonin. Both effects increase the functional connection between sensory and motor neurons thereby enhancing reflexive withdrawal from tactile stimuli. In Aplysia, these changes appear to contribute to several different forms of learning, such as short term sensitization, classical conditioning, and long-term sensitization.Please turn to Page 3...