Neurotoxicology and teratology
-
Neurotoxicol Teratol · Jan 2003
Level of prenatal cocaine exposure and infant-caregiver attachment behavior.
The objective of this longitudinal prospective cohort study was to determine whether level of prenatal cocaine exposure, or the interaction between level of prenatal cocaine exposure and contextual risk variables, was associated with a higher rate of infant-caregiver insecure attachment and disorganized attachment, or with alterations in infant crying or avoidant behavior, after controlling for prenatal exposure to alcohol, tobacco, and marijuana, the quality of the proximal caregiving environment, and other covariates. Subjects were 154 full-term 12-month-old infants (64 unexposed, 61 with lighter cocaine exposure, 29 with heavier cocaine exposure) and their primary caregivers from low-income, urban backgrounds. Exposure status was determined in the maternity ward by biologic assay (infant meconium and/or maternal or infant urine) and maternal self-report. ⋯ Contrary to popular perceptions, level of prenatal cocaine exposure was not significantly related to secure/insecure attachment status, disorganized attachment status, or rated level of felt security. Foster care status also was not associated with attachment status. However, heavier prenatal cocaine exposure, in interaction with maternal contextual variables (public assistance or multiparity) was associated with alterations in infant socio-affective behavior, including a higher level of behavioral disorganization, more avoidance of the caregiver, and less crying.
-
Neurotoxicol Teratol · Nov 2002
Prenatal chlorpyrifos exposure in rats causes persistent behavioral alterations.
Use of chlorpyrifos (CPF) has been curtailed due to its developmental neurotoxicity. In rats, postnatal CPF administration produces lasting changes in cognitive performance, but less information is available about the effects of prenatal exposure. We administered CPF to pregnant rats on gestational days (GD) 17-20, a peak period of neurogenesis, using doses (1 or 5 mg/kg/day) below the threshold for fetal growth impairment. ⋯ Promotional effects of acetylcholine (ACh) on cell differentiation may thus help to offset CPF-induced developmental damage that occurs through other noncholinergic mechanisms. Our results indicate that late prenatal exposure to CPF induces long-term changes in cognitive performance that are distinctly gender-selective. Additional defects may be revealed by similar strategies that subject the animals to acute challenges, thus, uncovering the adaptive mechanisms that maintain basal performance.
-
Neurotoxicol Teratol · May 2002
Prenatal alcohol and marijuana exposure: effects on neuropsychological outcomes at 10 years.
This report from a longitudinal study of the effects of prenatal alcohol and marijuana exposure investigates whether these drugs affect neuropsychological development at 10 years of age. Women were recruited from a medical assistance prenatal clinic and interviewed about their substance use at the end of each trimester of pregnancy, at 8 and 18 months, and at 3, 6, 10, 14, and 16 years. Half of the women were African American, and half were Caucasian. ⋯ Prenatal marijuana exposure also had an effect on learning and memory, as well as on impulsivity, as measured by a continuous performance task. The effects of prenatal alcohol and marijuana exposure persisted when other predictors of learning and memory were controlled. We continue to follow these offspring into the adolescent years when further neuropsychological deficits may become evident.
-
Neurotoxicol Teratol · May 2000
Comparative StudyThe influence of route of administration on the acute cardiovascular effects of cocaine in conscious unrestrained pregnant rats.
The intravenous route of administration, accessed via a subcutaneous vascular access port, has been recently suggested as an animal model for studying the developmental effects of maternal cocaine abuse in the pregnant and/or group-housed rat. The present study (1) assessed the cardiovascular effects of intravenous (IV) cocaine, delivered via bolus injection, in chronically catheterized near-term pregnant rats, and (2) compared the IV cardiovascular responses to those following cocaine delivered via the commonly employed subcutaneous (SC) and intragastric (IG) routes of administration. Pregnant gestation day 15 (GD15) young adult female Sprague-Dawley rats (n = 21) were anesthetized and catheters surgically implanted into the carotid artery, jugular vein, fundus of the stomach, and a subcutaneous pouch. ⋯ Finally, the pressor effects of IV cocaine paralleled the rapidly peaking arterial plasma levels of cocaine noted within 30 s after the initiation of drug injection. In sum, prominent effects of IV cocaine on maternal cardiovascular physiology are noted; as such, the recent reports of a lack of maternal/fetal toxicity following daily (3-6mg/kg) IV cocaine during GD8-21 are not due to use of an ineffective drug dose. It was equally clear that the SC and IG routes of exposure did not reproduce the cardiovascular component(s) of the expected physiological response to cocaine.