Biomedical Graduate Studies

Description of Research Expertise

Emotional responses to danger have profound and long-lasting effects on memory. In contrast with everyday recollections, emotional memories remain salient even years after a traumatic episode occurs. The enduring quality of emotional memories can be evolutionarily advantageous because it allows an organism to remember and therefore avoid dangerous situations. However, under extreme circumstances, traumatic memories can be repeatedly retrieved and such improper retrieval can disrupt daily life. The retrieval of fearful memories in inappropriate contexts is a trademark of several anxiety disorders, including post-traumatic stress disorder (PTSD) and phobias. Physiologically, abnormalities in the hippocampus have been associated with the etiology of several anxiety disorders. Yet despite the vast amount of research implicating the hippocampus in episodic emotional memories, the specific ways in which emotional information is stored in each hippocampal subregion are not well understood. My lab is interested in studying how memories are encoded along the longitudinal axis. Our data as well as several other studies have shown that the dorsal hippocampus specializes in spatial processing while the ventral hippocampus is more involved in emotion and anxiety. These findings raise the following questions: 1) What is the specific role of the dorsal and ventral hippocampus in episodic memory formation? 2) Do these regions work as independent modules processing distinct types of information? 3) How are emotional and spatial inputs integrated along the longitudinal hippocampal axis? To address these questions my lab conducts electrophysiological single unit recordings in freely moving mice tracking single cells for several days while animals learn different tasks. We combine this technique with computational, genetic, and behavioral tools. This multidisciplinary approach allows us to study how the intrinsic characteristics of different environmental stimuli influence the firing properties and long-term consolidation of hippocampal representations in the dorsal and ventral areas.