Comorbid Post Traumatic Stress Disorder and Alcohol Use Disorder in a Rodent Model Enhances Retrospective Memory-Linking
Abstract
Post-traumatic stress disorder (PTSD) is a devastating disorder that is commonly associated with alcohol use disorder (AUD) with a comorbidity rate of up to 79%. Both PTSD and AUD are characterized as disorders of learning and memory with maladaptive memories being a major hallmark of PTSD and AUD. Specifically, drug/fear related cues become disproportionally salient over non-drug/non-fear related cues enhancing the overgeneralization of drug/fear memories that results in increased drug craving/seeking or enhanced fear in a neutral context. Previous research suggests that if two contexts are encoded close in time, then fear experienced in the aversive context can permeate to the neutral context, a process known as retrospective memory-linking. There is, however, a lack of understanding of the impact of comorbid PTSD/AUD on retrospective memory-linking. The current study investigated retrospective memory-linking in our established animal model of comorbid PTSD/AUD. To accomplish this, we exposed male and female Wistar rats to restraint stress (RS) followed by chronic intermittent ethanol exposure (CIE). This was followed by the retrospective memory-linking task (MLT), that, first, involved exposure to a neutral context. This was followed by exposure to an aversive context, where the animal received an immediate footshock. Freezing behavior was used as an index to test how the fear of the aversive context was transferred to the neutral context. We found that the comorbid animals overgeneralized their fear from the aversive context to that of the neutral context significantly more than the non-comorbid animals. Additionally, the comorbid males maintained this overgeneralization of fear significantly longer than the comorbid females. This suggests that comorbid PTSD/AUD enhances retrospective memory-linking of fear-related memories, and this affect is exacerbated in males.
Start Time
16-4-2025 9:00 AM
End Time
16-4-2025 11:30 AM
Presentation Type
Poster
Presentation Category
Science, Technology and Engineering
Student Type
Graduate Student - Doctoral
Faculty Mentor
Justin Gass
Faculty Department
Biomedical Sciences
Comorbid Post Traumatic Stress Disorder and Alcohol Use Disorder in a Rodent Model Enhances Retrospective Memory-Linking
Post-traumatic stress disorder (PTSD) is a devastating disorder that is commonly associated with alcohol use disorder (AUD) with a comorbidity rate of up to 79%. Both PTSD and AUD are characterized as disorders of learning and memory with maladaptive memories being a major hallmark of PTSD and AUD. Specifically, drug/fear related cues become disproportionally salient over non-drug/non-fear related cues enhancing the overgeneralization of drug/fear memories that results in increased drug craving/seeking or enhanced fear in a neutral context. Previous research suggests that if two contexts are encoded close in time, then fear experienced in the aversive context can permeate to the neutral context, a process known as retrospective memory-linking. There is, however, a lack of understanding of the impact of comorbid PTSD/AUD on retrospective memory-linking. The current study investigated retrospective memory-linking in our established animal model of comorbid PTSD/AUD. To accomplish this, we exposed male and female Wistar rats to restraint stress (RS) followed by chronic intermittent ethanol exposure (CIE). This was followed by the retrospective memory-linking task (MLT), that, first, involved exposure to a neutral context. This was followed by exposure to an aversive context, where the animal received an immediate footshock. Freezing behavior was used as an index to test how the fear of the aversive context was transferred to the neutral context. We found that the comorbid animals overgeneralized their fear from the aversive context to that of the neutral context significantly more than the non-comorbid animals. Additionally, the comorbid males maintained this overgeneralization of fear significantly longer than the comorbid females. This suggests that comorbid PTSD/AUD enhances retrospective memory-linking of fear-related memories, and this affect is exacerbated in males.