Use of Renilla Bioluminescence to Illustrate Nervous Function

 

Tested Studies in Laboratory Teaching, 2007, Volume 28

Anne Goodwin

Abstract

Renilla mulleri is a bioluminescent soft coral with a nervous system composed of a simple nerve net. Bioluminescence in these animals occurs in a bright wave cross the surface, and is coordinated by nervous transmission. Groups of six students clustered around an animal can easily see the light wave without the use of magnification. The bioluminescent wave can be initiated by mechanical, electrical or chemical stimulation, and can be used to illustrate several concepts related to nervous function, including threshold, refractory period and adaptation. Students complete a homework assignment prior to the lab, in which they research mechanisms and functions of bioluminescence in Renilla and in other organisms. In the lab, each group gives a brief summary of the findings from the homework assignment; and examines the bioluminescent response of Renilla to touch. Students then make hypotheses about effects of varying the frequency and intensity of electrical stimulation, and about neurotransmitter and drug effects. These hypotheses are then tested by altering settings of the Grass stimulator, and by adding solutions of epinephrine, propranolol, and other chemicals. I used this lab in the context of the nervous systems unit of a sophomore Animal Physiology class, but the lab would also work well with more advanced classes, in which nervous control pathways could be better defined, or with introductory courses, which might involve discussions of bioluminescence or defense from predators. In this workshop, we will examine the morphology of Renilla specimens and initiate bioluminescence using mechanical, electrical and chemical stimuli. We will discuss applications of these experiments to various topics, and might also discuss other biological functions of these animals, including water transport, locomotion, and feeding responses.

Keywords:  neurons, neurotransmitters, bioluminescence, nerve net

Purdue University (2006)