Poster abstracts

Poster number 29 submitted by Courtney Dye

Chronic peripartum opioid exposure increases neuroinflammation and reduces maternal care in female rats

Courtney N. Dye (Neuroscience Program, The Ohio State University), Aliyah I. Webb (Department of Psychology, The Ohio State University), Madison P. Fankhauser (Department of Psychology, The Ohio State University), Jordyn J. Singleton (Department of Psychology, The Ohio State University), Kathryn M. Lenz (Department of Psychology; Department of Neuroscience, The Ohio State University), Benedetta Leuner (Department of Psychology; Department of Neuroscience, The Ohio State University)

Abstract:
7% of pregnant people use opioids. Opioid use during pregnancy can negatively impact maternal and offspring health. Those who use opioids are recommended to use medication assisted therapy (MAT), commonly buprenorphine, to prevent withdrawal symptoms. Opioids can bind to TLR4, an immune cell receptor, to impact neuroinflammatory signaling, and we have previously shown that neuroimmune alterations are important for the display of maternal behavior. Here, we used a rodent model to understand the impact of chronic peripartum opioid exposure or MAT on maternal caregiving and neuroinflammation. Female rats were exposed to vehicle (VEH), buprenorphine (BUP), or oxycodone (OXY), before, during, and after pregnancy. Opioid exposure reduced gestation length and maternal weight gain. Postpartum maternal caretaking behaviors including retrieval, huddling and nursing, and pup-directed sniffing and licking were reduced in opioid-exposed mothers as measured in pup retrieval tasks and home cage observations. Following behavioral testing, tissue was collected from brain regions important for facilitating caretaking, including the prefrontal cortex (PFC), nucleus accumbens (NAc), preoptic area (POA), and periaqueductal grey (PAG). Immunofluorescent labeling showed that BUP increased astrocyte expression in the PAG, while OXY increased microglia expression only in the PAG. Gene expression analysis also showed regional and treatment differences in immune transcripts. BUP and OXY increased TLR4 in the PFC. BUP increased TNF in the NAc, but decreased IL1B in the POA. OXY increased CD68 in the POA, and IL1B, TNF, and TLR4 in the PAG. Together, these results provide novel evidence of peripartum neuroimmune alterations following chronic opioid exposure that in part, could be mediating maternal care deficits. Thus, modulating neuroimmune activation could be a potential intervention for deficits in mothers exposed to opioids during pregnancy.

Keywords: Opioids, Neuroinflammation, Maternal behavior