Lab Mission Statement

To elucidate the neural and molecular underpinnings of addiction-related behaviors and memory formation. To provide a collaborative, stimulating and inclusive training environment that fosters critical thinking, professional growth and challenging established dogmas. To create a workspace where all lab members feel included and valued. The Memory, Epigenetics & Addiction Lab is committed to increasing diversity in science. We believe a diverse workforce is critical for generating novel, creative and innovative ideas and approaches to tackle complex questions.

Our lab combines animal models of addiction with molecular biological techniques to study epigenetic mechanisms underlying addiction susceptibility.

Drug addiction is a massive public health concern that inflicts extensive burdens on our economy and society.

Each year about 65 million individuals are exposed to opioids.

Of these, about 13 million misuse or abuse these drugs.

Why are some individuals more susceptible to abuse drugs? The interaction between genome (genetic makeup) and environment shapes the development of psychiatric diseases, including Substance Use Disorder. The etiology of addiction has a large genetic component and epidemiological studies suggest that Substance Use Disorder is heritable. The other side of that coin are epigenetic processes, which can be broadly defined as environmental influences on gene expression.

The emergence of epigenetic studies has provided a concrete mechanism for the long-held idea that psychiatric diseases are caused by complex interactions between environmental and genetic factors. The rapid explosion of publications on this topic over the past decade has brought new hope for identifying novel therapeutic targets and treatments for addiction.

Using multigenerational animal models to delineate epigenetic mechanisms underlying addiction vulnerability.

We have developed a multigenerational model to study the influence of drug exposure on future generations. Based on epidemiological data, our prediction was that the offspring of drug-exposed sires (fathers) would be more susceptible to develop addiction-like traits.

We are interested in two major questions:

  1. (1) How is the information passed on from fathers to their offspring? How can paternal drug taking alter the germline epigenome (sperm)? Which germline epigenetic reprogramming events are critical for shaping development toward addiction vulnerability in the next generation?

  2. (2) What has changed in the brain of the offspring produced by drug-treated fathers? What are the functionally relevant neuro-epigenetic processes that increase addiction-like behavior in the first generation progeny?

Our published work on this topic:

Toussaint AB, Foster W, Jones JM, Kaufmann S, Wachira M, Hughes R, Bongiovanni AR, Famularo ST, Dunham BP, Schwark R, Karbalaei R, Dressler C, Bavley CC, Fried NT, Wimmer ME, Abdus-Saboor I (2022) Chronic paternal morphine exposure increases sensitivity to morphine-derived pain relief in male progeny. Science Advances

Goetzl L, Thompson-Felix T, Darbinian N, Merabova N, Merali S, Merali C, Sanserino K, Tatevosian T, Fant B and Wimmer ME (2019) Novel biomarkers to assess in utero effects of maternal opioid use: First steps toward understanding short- and long-term neurodevelopmental sequelae. Genes Brain and Behavior. 18(6):e12583. PMCID: PMC7074845

Fant B, Wimmer ME, Swinford-Jackson SE, Maurer J, Van Nest D, Pierce RC (2019) Preconception maternal cocaine self-administration increases the reinforcing efficacy of cocaine in male offspring. Psychopharmacology. 236(12):3429-3437. PMCID: PMC6895412

Wimmer ME, Vassoler FM, White SL, Schmidt HD, Sidoli S, Han Y, Garcia BA and Pierce RC (2019) Impaired cocaine-induced behavioral plasticity in the male offspring of cocaine-experienced sires. European Journal of Neuroscience. 49(9):1115-1126. PMCID: PMC6559866.

Influence of paternal drug exposure on memory in the next generation

Some of the most debilitating consequences of addiction are the memory and cognitive deficits that often accompany chronic drug taking. Cognitive impairments are predictive of treatment retention and outcome, which is why some of the therapeutic strategies have focused on ameliorating drug-related neurocognitive insufficiencies. Clinical studies indicate that maternal drug exposure has deleterious effects on attention and impulsivity in offspring. However, the effect of paternal drug taking on cognitive function in offspring remains largely unstudied. Our lab uses the same multi-generational models of drug exposure to examine the long-term consequences of paternal drug taking on offspring memory.

Our published work on this topic:

Ellis AS, Toussaint AB, Knouse MC, Thomas AS, Bongiovanni AR, Mayberry HL, Bhakta S, Peer K, Bangasser DA and Wimmer ME (2020) Paternal morphine self-administration produces object recognition memory deficits in female, but not male offspring. Psychopharmacology . 237(4):1209-1221, PMCID: PMC7124995

Wimmer ME, Briand LA, Fant B, Guercio LA, Arreola AC, Schmidt HD, Sidoli S, Han Y, Garcia BA, Pierce RC (2017) Paternal cocaine taking elicits epigenetic remodeling and memory deficits in male progeny. Molecular Psychiatry. 22(11):1641-1650, PMCID PMC5568460

White SL, Vassoler FM, Schmidt HD, Pierce RC, Wimmer ME (2015) Enhanced anxiety in male offspring of sires that self-administered cocaine. Addiction Biology. 21(4):802-10. PMCID PMC4626434

Molecular underpinnings of relapse

Substance Use Disorder is a chronic relapsing disease with high relapse rates that are on par with other prevalent diseases such as hypertension and asthma. A better understanding of the molecular mechanisms underlying drug relapse is needed to improve therapies for the treatment of addiction. Our lab relies on the drug self-administration and reinstatement model to examine the molecular pathways involved in drug seeking behavior and drug relapse.

Our published work on this topic:

Mayberry HL, Bavley CC, Karbalaei R, Peterson DR, Bongiovanni AR, Ellis AS, Downey SH, Toussaint AB, Wimmer ME (2022) Transcriptomics in the nucleus accumbens shell reveal sex- and reinforcer-specific signatures associated with morphine and sucrose craving. Neuropsychopharmacology.

Wimmer ME, Fant B, Swinford-Jackson SE, Testino A, Van Nest D, Abel T and Pierce RC (2019) H3.3 barcoding of nucleus accumbens transcriptional activity identifies novel molecular cascades associated with cocaine self-administration in mice. Journal of Neuroscience. 3;39(27):5247-5254. PMCID: PMC6607753.

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