Wesley (Wes) P. Jordan

Animal Models of Psychopathology

Human disorders such as schizophrenia and depression afflict millions of people. Determining the brain substrates of these disorders, however, is exceedingly difficult. Current brain imaging techniques provide only a limited insight into the working of a diseased brain. One way to increase our understanding of the nature of these disorders is to develop animal models. Many functional and physiological similarities exist across species. For example, all vertebrate brains use the same neurotransmitter systems. By studying simpler nervous systems we can learn the fundamental principles that govern the function of all brains. Using other organisms also allows for the experimental analysis of the effects of new drugs--something too dangerous to first attempt in human patients.

An animal model does not have to reproduce all symptoms of a human disorder to be effective. Thus, in studying schizophrenia, we do not have to work with rats that have a major thought disorder and suffer from hallucinations. Rather, we need to work with animals that suffer a specific symptom similar to those suffered by schizophrenic patients. Schizophrenic patients are unable to filter out certain types of sensory information. Rats can be made to have this same problem by giving them drugs such as amphetamine or PCP. Once this symptom has been produced in the rats, the experimenter can study how other drugs or behavioral manipulations can reduce the symptom. Finding therapies that work in the animal model may one day lead to more effective treatments for human beings.

In our lab students have studied the role of Prozac in learning in an animal model of depression; the effects of Prozac on fear conditioning; and the role of the atypical antipsychotics in two models of schizophrenia.

We have also investigated the claims that the herb St. John's Wort has anti-depressive properties. This is important research because of the large number of people who self-administer this substance without adequate information about its effects.