Effect of prenatal opioid exposure on cholinergic development

Opioid drugs such as methadone or buprenorphine are often used in the manag ement of pregnant addicts. These drugs are generally thought of as nonterat ogenic and preferable to repeated cycles of withdrawal in utero. However, e vidence exists that perinatal exposure to these opioids delays and disrupts cholinergic development, particularly in the striatum. Acetylcholine (ACh) content and the expression of choline acetyltransferase protein and mRNA a re reduced in the early postnatal period by prenatal opioid exposure in the rat. Although these indicators of the cholinergic phenotype return to norm al levels over time, the activity of the cholinergic neurons remains disrup ted, with a large increase in ACh turnover rate. The mechanism of these eff ects is unknown, but may involve changes in the expression of nerve growth factor, which is reduced by opioid exposure. Copyright (C) 2000 National Sc ience Council. ROC and S. Karger AG, Basel.