Princeton Neuroscience Institute

Our central interest is in brain monoamine neurotransmitters and their role in physiology and behavior, and especially how these brain chemicals relate to stress and mental illness. In addition, we are interested in how basic biological factors, drugs, and stress affect the production of new brain cells in adult animals. We explore these questions through recording single unit activity in behaving animals, c-Fos expression in brain, and immunohistochemical labeling of proliferating brain cells. The following types of questions exemplify our research interests. How are various aspects of motor output, including those associated with fatigue, related to the activity of brain serotonergic neurons. We have found, for example, that the activity of various brain stem serotonergic neurons is related to repetitive, unlearned movements, such as locomotion, chewing, and respiration. We have also found that the activity of these neurons becomes suppressed as fatigue sets in, for example, during treadmill-induced locomotion. Using c-Fos expression, we are examining how different stressors activate a variety of brain stem neuronal groups, such as the raphe nuclei and the locus coeruleus. We are especially interested in examining any resulting long-term changes. Finally, we are studying how drugs such as marijuana affect the production of new brain cells in adult animals.