Investigators
Research Project Leaders
Project 1- Molecular Mechanisms of Memory Consolidation in the Amygdala-Hippocampal Circuit
| Barbara Gisabella, PhD Assistant Professor, |
Sleep and memory dysfunction are key features across many psychiatric disorders. Memories are strengthened during sleep , a process that may be disrupted in people with psychiatric disorders. For example, patients with schizophrenia commonly display sleep disturbances and memory consolidation deficits. In comparison, people suffering from post-traumatic stress disorder have sleep disruption and nightmares associated with heightened fear memories.
A growing number of studies support the theory that infrequently used synapses are decreased during sleep to strengthen memory processing by enhancing the signal to noise ratio of connections in the brain.
Our published and preliminary data demonstrates that brain synapses in neurons that encoded fear memory are strengthened during sleep while other synapses are largely decreased. Furthermore, our data pointing to differences between two brain regions involved in processing emotional memories, the amygdala and the hippocampus, indicates that memory processes in two key areas of the emotional memory circuit are differentially regulated during sleep.
There is a critical knowledge gap regarding the molecular pathways involved in strengthening memories during sleep. Our studies will use a combination of state-of-the-art single nucleus RNA sequencing, spatial transcriptomics and targeted mass spectrometry along with a novel transgenic mouse model, and complementary human brain postmortem studies, to create a much-needed foundation of molecular signaling pathways involved in upscaling and downscaling of synapses in the fear memory circuit during sleep and identify new molecules involved in this process.
The expected data will serve as a foundation for future studies examining disruption of these pathways in psychiatric disorders, and studies designed to identify novel targets for therapeutic strategies.
Project 2 - Host-pathogen molecular and cardiovascular interaction during influenza infection
| Brigitte Martin, PhD Assistant Professor Department of Cell & Molecular Biology bmartin1@umc.edu |
Influenza viral infection impacts up to 41 million people per year and can have significant impacts on morbidity and mortality. The detection of subtle changes in cardiovascular physiology in response to influenza infection is not only important for earlier diagnosis and better prognosis of symptomatic carriers, but also useful to diagnose asymptomatic carriers of the virus and provide better infectious disease surveillance.
Overall, we hypothesize that a localized inflammatory event in the respiratory system caused by the influenza virus infection leads to systemic changes in normal cardiovascular physiology, biomarkers, and viral genomic heterogeneity that can be altered by obesity and timely admission of antiviral therapeutics. The identification of novel biomarkers during an inflammatory event could significantly improve predictions for cardiovascular events. Additionally, more thorough genomic investigation of replicating influenza populations can lead to better surveillance and prediction of ongoing and emerging events.
We hope to modify cardiovascular events caused by respiratory virus infection (both during and after) with proinflammatory state of obese mice or reduction of inflammatory events in a timely manner with varying oseltamivir treatment timings. The expectation is to define markers that are present during an influenza virus infection that correlate with disease and changes in physiological homeostasis specifically for each inflammatory state (proinflammatory caused by obesity and anti-inflammatory caused by antivirals).
This study will investigate a major gap in knowledge by performing detailed analysis of cardiovascular physiology (histology, flow cytometry, and echocardiography), host molecular changes (RNA-seq and proteomics), and viral populations (real-time (quantitative) PCR [RT(q)-PCR] and RNA-seq) associated with localized respiratory viral infection with obesity and antiviral treatment or chemoprophylaxis.
Project 3 - Sex Differences in Addiction
 | Amy Kohtz, PhD Assistant Professor Department of Psychiatry & Human Behavior akohtz@umc.edu
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The inability to maintain abstinence is a trademark of addiction yet effective maintenance therapies remain elusive. Women may face unique issues with substance abuse treatment, as research indicates that psychological and biological responses to drugs of abuse differ in women compared to men. Women tend to show greater drug dependence, progress more quickly from casual drug use to dependence, have greater difficulty quitting, and have shorter periods of abstinence than men. These effects have been similarly observed in female animal models. Thus, understanding circuit and molecular signatures that drive increased drug-seeking among females is critical to the development of effective SUDs therapies. We have developed a novel behavioral model termed the seeking-persistence paradigm (SPP) that was adapted from standard drug abstinence paradigms. The seeking-persistence paradigm is used to investigate the influence of intervention during initial abstinence on long-term drug-seeking behaviors. Indeed, cocaine-seeking during initial abstinence strongly correlates with seeking after drug-abstinence. These results reflect clinical studies indicating that craving during initial abstinence predicts relapse rates. We have previously identified that the dorsal hippocampus is a crucial target for sex-specific modulation of cocaine-seeking on ED1. Prior reports show projections from the dorsal hippocampus selectively modulate memory strengthening or facilitate extinction, dependent on whether they terminate in the prelimbic cortex, or infralimbic cortex, respectively. Our preliminary data suggest that sexually-divergent projections of the dHPC to prelimbic and infralimbic cortical areas may underlie sex differences in persistent cocaine seeking during extinction.
Herein, we will test the hypothesis that hippocampal-prelimbic cortex neurocircuitry drives the behavioral expression of cocaine memory strengthening in female rats (Aim 1), and hippocampal infralimbic cortex neurocircuitry drives the behavioral expression of cocaine memory extinction in male rats (Aim 2). In each aim, we will combine chemogenetic (DREADDs), and functional genomic methods (viral tracing, RNA-sequencing, and single-cell RNA-sequencing), to ultimately provide key information on the impact of context-induced cocaine seeking behavior on relapse risk through the novel analysis of the contribution of memory systems (dHPC->PL, dHPC->IL) and sex differences therein.