BARNES , J. W.; SHERMAN, R. L.; HUSTON , J. P.; RUSSO, A.; SPIELER, R. E.*; Nova Southeastern University, Ft. Lauderdale; Nova Southeastern University, Ft. Lauderdale; University of Duesseldorf, ; University of California, Long Beach; Nova Southeastern University, Ft. Lauderdale: The Yellow Stingray, Urobatis jamaicensis , As A Model For Studying Cerebellar Function In Vertebrates.

Fishes, in general, have several advantages as vertebrate models for basic brain function. They are phylogenetically closer than mammals to the basic vertebrate blueprint and thus allow behavioral and neurological studies of fundamental brain systems without the interaction of more recently evolved functions. Further, the absence of a highly developed telencephalon allows ready access to many structures without cerebral interference. However, a disadvantage of working with most fishes is the relatively small size of the brain that often hinders or precludes the use of many standard neurological techniques. In contrast, a group of chondrichthians, the stingrays, Dasyatoidea, has a brain size rivaling mammalian rodent models. Of particular interest to our research, stingrays, like mammals, have a large, complex, three-lobed cerebellum. However, in the yellow stingray these lobes are completely separated. Thus, the lobes can be individually manipulated to examine behavioral correlates of specific lobes. For example, ablation of the center lobe (aka. anterior caudal lobule) causes a fixed-pattern hyperactivity. Yellow stingrays are abundant in many areas, they are hardy, and tolerate anesthesia and the surgical procedures well. A more complete elucidation of cerebellar function awaits further physical and pharmacological ablative studies but the potential for these animals as vertebrate models of cerebellar-controlled behavior is clear.