Scott Heldt

As a behavioral neuroscientist, my general goal is to continue research directed toward understanding the neural mechanisms involved in the production and reduction of conditioned fear and anxiety, with special emphasis focused on GABAergic mechanisms and influences. The results of numerous studies have demonstrated that the amygdala and hippocampus play major roles in neural processes involved in the acquisition, retention, and extinction of conditioned fear. Many of these studies have demonstrated that changes in fast glutamatergic transmission play an important role in the formation of emotional memories associated with the acquisition and extinction of fear. However, there are converging lines of evidence suggesting that changes in GABAergic transmission may also be involved in these processes. Thus, research designed to examine the role of GABAergic systems may provide a better understanding of the mechanisms that influence emotional memories and behaviors associated with anxiety and fear.

In Dr. Kerry Ressler’s lab, I have received training in the use of numerous molecular techniques useful for understanding of the molecular and genetic processes involved in the structural and functional plasticity including, PCR, in situ hybridization, autoradiography, western blotting, electrophoresis, immunocytochemistry, plasmid cloning, and cutting edge transgenic and viral vector techniques to manipulate the temporal and spatial expression of genes in the brain. In addition, my time at Emory University has provided me with the opportunity to incorporate into my research a broad variety of behavioral tests useful for investigating experimental manipulations including, the elevated plus maze, Morris water maze, open field apparatus, forced swim test, horizontal wire test, prepulse inhibition, rotarod apparatus, startle, fear-potentiated startle, and conditioned freezing.

Among current projects, I have recently examined changes in the expression of GABA-related genes in the amygdala and hippocampus after the acquisition, retrieval, and extinction of Pavlovian fear. In addition, I have examined the function of amygdala and hippocampal alpha1-GABA(A) receptors in these processes using alpha1-GABA(A) inducible knockout mice. A related line of my research aims at elucidating the role of localized GABA(A) receptor subtypes in baseline behavior as well as the behavioral and pharmacological effects of benzodiazepines (BZs). For example we are currently investigating conditioned fear, drug-induced sedation, and seizure threshold in mice with regional deletion of the alpha1-GABA(A) receptor subunit.