Roberts, S.A.*; Moore, P.A.; Huber, R.; Heckman, C.; Cayer, M.: Immunocytochemical Localization of Met-enkephalin in Crayfish Eye Stalk

Experimental investigation into the effect of chemical signals in the nervous system of crayfish has shown certain neurotransmitters, such as seratonin and dopamine, have the capability of altering the aggressive tendencies of crayfish in a hierarchical community. While such studies are becoming well documented, a third group of polypeptide neurotransmitters, enkephalins, have gone relatively unstudied. Enkephalins are believed to function in a manner echoing that of seratonin and dopamine, however, the lack of research into these chemical signals provides only a small platform from which to embark onto further study. The goals of this study are two fold. First, it attempts to determine the relative dispersion of Met-enkephalin in the crayfish eye stalk, where unusually large amounts of enkephalins have been reported. Secondly, it strives to identify the specific location of high concentration centers of the neurotransmitter in the hopes of lending information towards the functioning of these chemicals within the crayfish nervous system and possible behavioral effects caused by the presence of the neurotransmitter. Results appear to indicate localization of enkephalin or enkephalin-like molecules within the eye stalk, depicting specified use of the neurotransmitter. Ultimately, the wide range of organisms that utilize enkephalins in their nervous systems provides a strong possibility for extrapolation of enkephalin effects to other complex organisms form a crayfish basis.