Effects of prenatal methamphetamine exposure on birth outcomes, brain structure, and neurodevelopmental outcomes

Impact of altered environment and early postnatal methamphetamine exposure on serotonin levels in the rat hippocampus during adolescence

BACKGROUND

Methamphetamine (MA) is a highly abused psychostimulant across all age groups including pregnant women. Because developing brain is vulnerable by the action of drugs, or other noxious stimuli, the aim of our study was to examine the effect of early postnatal administration of MA alone or in combination with enriched environment (EE) and/or stress of separate housing, on the levels of serotonin (5HT) in the hippocampus of male rat pups at three stages of adolescence (postnatal day (PND) 28, 35 and 45). MA (5 mg/kg/ml) was administered subcutaneously (sc) to pups (direct administration), or via mothers' milk between PND1 and PND12 (indirect administration). Controls were exposed saline (SA). Pups were exposed to EE and/or to separation from the weaning till the end of the experiment.

RESULTS

On PND 28, in sc-treated series, EE significantly increased the muted 5HT in SA pups after separation and restored the pronounced inhibition of 5HT by MA. No beneficial effect of EE was present in pups exposed to combination of MA and separation. 5HT development declined over time; EE, MA and separation had different effects on 5HT relative to adolescence stage.

CONCLUSIONS

Present study shows that MA along with environment or housing affect 5HT levels, depending on both the age and the method of application (direct or indirect). These findings extend the knowledge on the effects of MA alone and in combination with different housing conditions on the developing brain and highlight the increased sensitivity to MA during the first few months after birth.

Trends in Drug Tests among Children: A 22-Year Retrospective Analysis

There are several pathophysiological outcomes associated with substance abuse including metabolic disbalance, neurodegeneration, and disordered redox. Drug use in pregnant women is a topic of great concern due to developmental harm which may occur during gestation and the associated complications in the neonate after delivery. We sought to determine what the trajectory of drug use is like in children aged 0-4 years and mothers of neonates. Urine drug screen (UDS) results were obtained of our target demographic during 1998-2011 and 2012-2019 from LSU Health Sciences Center in Shreveport (LSUHSC-S). Statistical analysis was performed using R software. We observed an increase in cannabinoid-positive UDS results in both Caucasian (CC) and African American (AA) groups between 1998-2011 and 2012-2019 periods. Cocaine-positive UDS results decreased in both cohorts. CC children had higher UDS positive results for opiates, benzodiazepines, and amphetamines, while AA children had a higher percentage for illicit drugs such as cannabinoids and cocaine. Neonate's mothers had similar UDS trends to that in children during 2012-2019. Overall, while percentage of positive UDS results for both AA and CC 0-4 year old children started to decline for opiate, benzodiazepine, and cocaine during 2012-2019, cannabinoid- and amphetamine (CC)-positive UDS steadily increased. These results suggest a shift in the type of drug use by mothers from opiates, benzodiazepines, and cocaine to cannabinoids and/or amphetamines. We also observed that 18-year-old females who tested positive for opiates, benzodiazepine, or cocaine had higher than average chances of testing positive for cannabinoids later in life.

Effects of prenatal methamphetamine exposure on spatial cognition and hippocampal synaptic plasticity in adolescent rats

Global rise in methamphetamine (MA) abuse during pregnancy has placed a large number of children at risk for the adverse consequences of prenatal methamphetamine exposure (PME). While behavioral and neurocognitive deficits of PME have been extensively studied in humans and adult rodents, far less is known regarding the sex- and dose-dependent effects of PME as well as the underlying mechanisms. Adolescence in nonhuman primates is also a less explored territory. In the present study, PME was inducted by oral treatment to pregnant rats on gestational days 15-19 with either low-dose (0.1 mg/ml) or high-dose (0.6 mg/ml)) of MA. The cognitive effects of PME were then evaluated in two adolescence age-intervals: early adolescent (started on postnatal day (PND) 21) and mid adolescent (started on PND 33), among male and female rat offspring using Morris water maze (MWM) test. Alterations in hippocampal synaptic plasticity in Schaffer collaterals-CA1 pathway were also measured in vitro. Results of behavioral test showed that PME led to serious deficits of learning and memory abilities in both male and female rat offspring. PME also depressed LTP in most of the PME subgroups. Moreover, 21-day-old rats were more sensitive to PME-induced cognitive impairment in MWM tasks, but not in hippocampal synaptic plasticity, than 33-day-old rats. No sex-dependent effects of PME were found on the cognitive function and synaptic plasticity. These findings confirmed that PME impacted negatively on cognitive performance in prepubertal male and female rats, and the impairment of hippocampal synaptic functions might partly play a significant role in these effects.