Developmental 3,4-methylenedioxymethamphetamine (MDMA) impairs sequential and spatial but not cued learning independent of growth, litter effects or injection stress.
Previously, we have shown that rats administered MDMA from postnatal (P) days 11-20 had reductions in body weight during the period of treatment and as adults they had deficits in sequential and spatial learning and memory. In the present study, to control for weight reductions, we used litters with double the number of offspring to induce growth restriction comparable to that of standard size litters treated with MDMA. Litters were treated twice daily from P11 to 20 with vehicle or MDMA (20 mg/kg) or only weighed. Males, but not females, exposed to MDMA had longer latencies and more errors in the Cincinnati water maze compared to males of the other treatments. In the Morris water maze (210 cm pool, 10x10 cm platform), the MDMA animals were impaired relative to all other treatments during acquisition. Only the MDMA females showed deficits when the platform was shifted to a new location, however, both MDMA males and females were impaired when the location of the platform was again shifted and a reduced platform (5x5 cm) used. No differences were observed in the ability to swim a straight channel, locate a platform with a cue, or the endocrine response to forced swim among the treatment groups. No differences were seen between animals injected with saline and those only weighed. The data suggest that factors, such as growth retardation, multiple injections, or the composition of the litter, do not affect the development of learning and memory impairments resulting from P11 to 20 MDMA exposure. The large litter approach offers a novel method to control for undernutrition during the preweaning period in rodents.
Williams
Michael T
MT
Pharmacology Research Center, Cincinnati Children's Research Foundation and University of Cincinnati College of Medicine, 45229-3039, Cincinnati, OH, USA
Morford
LaRonda L
LL
Wood
Sandra L
SL
Rock
Stephanie L
SL
McCrea
Anne E
AE
Fukumura
Masao
M
Wallace
Tanya L
TL
Broening
Harry W
HW
Moran
Mary S
MS
Vorhees
Charles V
CV
D015104:3,4-Methylenedioxyamphetamine / Q000008:administration & dosage / Q000009:adverse effects* / Q000031:analogs & derivatives*; D000324:Adrenocorticotropic Hormone / Q000097:blood; D000375:Aging; D000818:Animals; D000831:Animals, Newborn / Q000254:growth & development; D001522:Behavior, Animal; D001824:Body Constitution; D001835:Body Weight; D016022:Case-Control Studies; D003345:Corticosterone / Q000097:blood; D003463:Cues; D018690:Excitatory Amino Acid Agonists / Q000008:administration & dosage / Q000009:adverse effects*; D005260:Female; D007859:Learning Disabilities / Q000209:etiology*; D008098:Litter Size / Q000187:drug effects* / Q000502:physiology; D008297:Male; D018782:Maze Learning / Q000187:drug effects; D010298:Parity; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D011930:Reaction Time; D012691:Serial Learning / Q000187:drug effects*; D012737:Sex Factors; D013037:Spatial Behavior / Q000187:drug effects*; D013312:Stress, Physiological; D013550:Swimming / Q000502:physiology; D013997:Time Factors
D018690:Excitatory Amino Acid Agonists; D015104:3,4-Methylenedioxyamphetamine; D000324:Adrenocorticotropic Hormone; C051800:3,4-methylenedioxyethamphetamine; D003345:Corticosterone