The Neurophysiology Laboratory - Dr. N. Bradley Keele

The functional role of limbic system neuronal excitability in emotional behavior.

My lab is primarily focused on the neurobiology of complex emotional behaviors, such as aggression and violence, fear and anxiety disorders, and depression. We examine the contribution of epilepsy-like neuronal hyperexcitability to emotional behavior and psychopathology. Aggression, while not a psychiatric disorder itself, is problematic in the treatment of many other disorders. Therefore, we need to investigate further the biological mechanisms involved in complex emotional behaviors to promote the development of safer, more effective strategies to treat aggression.

We use an animal model to study the functional changes of single nerve cells in the amygdala, a part of the brain important for controlling fear and aggression. Besides its role in emotion, the amygdala is also often the locus of abnormal electrical discharges that underlie epilepsy. We hypothesize that epilepsy-like mechanisms of cellular excitability in the amygdala contribute to the function and dysfunction of this important limbic nucleus. Our recent findings have shown that the combination of individual housing coupled with serotonin, produce behaviorally aggressive animals that also exhibit low anxiety, and deficient fear behaviors. This constellation of behaviors is also found in humans characterized as primarily impulsively aggressive. Further, amygdala neurons from behaviorally aggressive animals show epilepsy-like neural activity. Presently we are engaged in dissecting the cellular and molecular changes in the amygdala that contribute to disturbed emotional behaviors, and also examining in our model the behavioral effects of mood-stabilizers used to treat other psychiatric disorders.