Prenatal opioid exposure inhibits microglial sculpting of the dopamine system selectively in adolescent male offspring

Caroline J. Smith, Tania Lintz, Madeline J. Clark, Karen E. Malacon, Alia Abiad, Nicholas J. Constantino, Veronica J. Kim, Young C. Jo, Yanaira Alonso-Caraballo, Staci D. Bilbo, Elena H. Chartoff

Research output: Contribution to journalArticlepeer-review

7 Scopus citations


The current opioid epidemic has dramatically increased the number of children who are prenatally exposed to opioids, including oxycodone. A number of social and cognitive abnormalities have been documented in these children as they reach young adulthood. However, little is known about the mechanisms underlying developmental effects of prenatal opioid exposure. Microglia, the resident immune cells of the brain, respond to acute opioid exposure in adulthood. Moreover, microglia are known to sculpt neural circuits during typical development. Indeed, we recently found that microglial phagocytosis of dopamine D1 receptors (D1R) in the nucleus accumbens (NAc) is required for the natural developmental decline in NAc-D1R that occurs between adolescence and adulthood in rats. This microglial pruning occurs only in males, and is required for the normal developmental trajectory of social play behavior. However, virtually nothing is known as to whether this developmental program is altered by prenatal exposure to opioids. Here, we show in rats that maternal oxycodone self-administration during pregnancy leads to reduced adolescent microglial phagocytosis of D1R and subsequently higher D1R density within the NAc in adult male, but not female, offspring. Finally, we show prenatal and adult behavioral deficits in opioid-exposed offspring, including impaired extinction of oxycodone-conditioned place preference in males. This work demonstrates for the first time that microglia play a key role in translating prenatal opioid exposure to changes in neural systems and behavior.

Original languageEnglish (US)
Pages (from-to)1755-1763
Number of pages9
Issue number10
StatePublished - Sep 2022
Externally publishedYes

Bibliographical note

Funding Information:
This work was supported by NIH R21DA048399 to EHC and SDB, NIH F32ES029912 to CJS, and by a Harvard University Mind, Brain, and Behavior Faculty Research Award to EHC and SDB.

Publisher Copyright:
© 2022, The Author(s), under exclusive licence to American College of Neuropsychopharmacology.


Dive into the research topics of 'Prenatal opioid exposure inhibits microglial sculpting of the dopamine system selectively in adolescent male offspring'. Together they form a unique fingerprint.

Cite this