International Journal of Developmental Neuroscience
August 1, 2004
Charles V. Vorhees, Tracy M. Reed, Matthew R. Skelton et al.
76 citations
Rats exposed to MDMA on postnatal days 11–20 showed consistent impairments in spatial learning and memory in the Morris water maze when tested on that maze first, with longer latencies, longer path lengths, and greater cumulative distance from the goal compared to saline controls. On probe trials, MDMA-treated animals that received the water maze first had increased distance from the target site. No MDMA effects were observed on cued trials, straight channel swimming, or working memory, indicating the drug did not impair swimming ability or basic task skills. No MDMA effects were found on the Barnes maze, though interpretation was limited by poor performance on that task.
Brain Research
March 25, 2003
Michael T. Williams, Laronda L. Morford, Sandra L. Wood et al.
66 citations
Rats given MDMA from postnatal days 11 to 20 showed lasting deficits in spatial learning and memory, even when growth restriction from the drug was matched by raising rats in larger litters. Males exposed to MDMA took longer and made more errors in the Cincinnati water maze than control males. In the Morris water maze, MDMA-treated rats of both sexes were impaired during initial learning. Only females showed deficits when the platform was first moved, but both sexes were impaired after a second move with a smaller platform. No differences appeared in swimming ability, cued navigation, or stress hormone responses. Growth retardation, injections, or litter size did not account for the learning impairments.
Developmental Neuroscience
January 1, 2009
Charles V. Vorhees, Tori L. Schaefer, Matthew R. Skelton et al.
40 citations
Treating rat pups with MDMA during different preweaning periods (postnatal days 1–5, 6–10, 11–15, or 16–20) produced lasting effects. The three highest doses (15, 20, and 25 mg/kg) reduced spontaneous locomotor activity during the first 10 minutes of testing, especially when given on days 1–5 or 6–10. All MDMA-treated groups showed impaired allocentric learning in the Morris water maze during both acquisition and reversal phases; the two highest doses also impaired performance on the small platform phase. No effects were found on anxiety, novel object recognition, or egocentric learning, though a nonsignificant trend appeared. The results indicate that allocentric and egocentric learning have different exposure-duration sensitivities and that the stress hyporesponsive period is not critical for MDMA's effects on allocentric learning.
Psychopharmacology
June 1, 2009
Matthew R. Skelton, Tori L. Schaefer, Nicole R Herring et al.
31 citations
Treating young rats with either MDMA or the club drug 5-MeO-DIPT from postnatal days 11 to 20 caused lasting cognitive and behavioral changes, but the patterns differed between the two drugs. MDMA-treated animals showed increased anxiety, deficits in spatial and path integration learning, and memory problems. 5-MeO-DIPT-treated animals had spatial learning deficits but no impairments in spatial memory or path integration learning, and they were hyperactive when given a challenge dose of methamphetamine. The findings indicate that developmental exposure to either drug produces distinct behavioral effects.
J Comp Neurol
August 1, 2012
Ann M. Hemmerle, Jonathan W. Dickerson, Nicole R Herring et al.
29 citations
A single dose of MDMA (ecstasy) alters the expression of neurotrophins and their receptors in several regions of the adult rat brain, suggesting that the drug can influence brain plasticity and potentially contribute to its long-term effects.
The International Journal of Neuropsychopharmacology
January 11, 2013
Tori L. Schaefer, Curtis E. Grace, A Braun et al.
24 citations
In rats, treatment with the recreational drug MDMA during a developmental period equivalent to the human third trimester causes long-term spatial and egocentric learning and memory deficits, along with serotonin reductions. Pretreatment with the antidepressant citalopram, a selective serotonin reuptake inhibitor, did not prevent these cognitive deficits. Unexpectedly, citalopram alone produced learning deficits as severe as those caused by MDMA. These are the first findings showing cognitive impairments from developmental exposure to a selective serotonin reuptake inhibitor, suggesting the need for further research on the long-term safety of antidepressants during pregnancy.
Neurotoxicology and Teratology
January 1, 2010
Devon L Graham, Nicole R Herring, Tori L. Schaefer et al.
13 citations
Acute exposure to the club drugs MDMA (Ecstasy) and Foxy increases the stress hormone corticosterone in rats at all ages tested—preweaning, juvenile, and adulthood. Blood glucose also rises at all stages except in juveniles. No differences were found between males and females. These hormonal and metabolic changes may contribute to the behavioral and cognitive impairments previously linked to these drugs.
The open neuropsychopharmacology journal
January 1, 2012
Devon L Graham, Nicole R Herring, Tori L. Schaefer et al.
4 citations
Binge doses of methamphetamine (MA) cause brief epileptiform brain activity in about half of rats and longer seizures in some, while MDMA produces no significant brain-wave abnormalities or muscle jerks. The drug Foxy (5-MeO-DIPT) triggers seizures in all rats shortly after the first dose, with muscle jerks appearing soon after injection. These effects were observed in male rats implanted with cortical electrodes and given four injections of each drug (10 mg/kg every two hours), a regimen that mimics the neurochemical changes seen in chronic users. The findings indicate that MDMA does not increase EEG abnormalities under these conditions, whereas MA and especially Foxy produce severe brain-activity disturbances.
Toxicology Reports
October 11, 2016
Michael T. Williams, Matthew R. Skelton, Ian D. Longacre et al.
3 citations
Rats given MDMA during a period of brain development equivalent to late human pregnancy showed lasting changes in brain cell structure. In the nucleus accumbens, dendrites were shorter with fewer spines. In the dentate gyrus, dendritic length decreased but spine density increased. In the entorhinal cortex, both basilar and apical dendritic lengths were reduced. These structural changes occurred in brain regions linked to learning and memory, matching previously observed cognitive deficits in MDMA-exposed animals.