Cognitive Impairment Models Using Complementary Species

Excerpt

In the development and use of animal models of cognitive dysfunction, it is important to develop complementary models to exploit the unique advantages of the different species. Nonmammalian vertebrates such as fish provide the opportunity to directly observe neurodevelopmental processes and determine the impact of developmental permutations on learning and memory. Zebrafish in particular are valuable because of the availability of morpholine techniques to transiently suppress specific parts of genomic expression. Invertebrate models such as C. elegans and drosophila provide other advantages, particularly the elegant genetic manipulations available. The simple nervous systems in these models are useful in determining mechanisms of cognitive function. The development of new methods for high-throughput tests of cognitive function for fish can provide a means for rapid screening of potential toxic agents as well as promising therapeutic agents. It is equally important to develop specific tests of various aspects of cognitive function, including habituation, associative learning, memory, and attention as well as to be able to differentiate changes in sensorimotor function from cognition. Key in the use of nonmammalian models is the determination of which mechanisms of cognitive function are similar to mammals and which are different. Nonmammalian models can be used in concert with classic mammalian models to determine the neural bases of cognitive function and to aid in the discovery of toxicants and potential therapeutic agents.