Prenatal cocaine exposure produces gender-specific motor effects in aged rats.
This investigation employed a longitudinal analysis of a complex motor skill in rats that were exposed prenatally to cocaine. Offspring were derived from four maternal treatment groups: 50 mg/kg cocaine, their pair-fed controls, 25 mg/kg cocaine, and freely fed controls. Cocaine was administered via gavage from gestation day 6-20. A maternal fostering procedure was used. Pairs of male and female littermates began training when 9, 13, or 19 months old. The behavioral procedure involved fixed-ratio (FR) lever pressing to obtain brief periods of wheel running. The oldest males from the 50 mg/kg, 25 mg/kg, and pair-fed groups performed significantly fewer wheel revolutions per opportunity than females or freely fed males. In general, animals earned fewer opportunities to run as the FR requirement was increased over sessions. However, within each age-by-gender group, subjects from the four treatment groups performed equivalent amounts of lever pressing. The specific effect on the motor aspect of the procedure may have resulted from a reduction of motor coordination, balance, or strength, or a diminished capacity of wheel running to serve as a reinforcing stimulus in a cocaine-sensitive subgroup.
Markowski
V P
VP
Department of Environmental Medicine, University of Rochester School of Medicine, NY 14642, USA. markowski@ehsct7.envmed.rochester.edu
Cox
C
C
Weiss
B
B
D000818:Animals; D001835:Body Weight / Q000187:drug effects; D003042:Cocaine / Q000633:toxicity*; D003216:Conditioning, Operant / Q000187:drug effects; D004032:Diet; D005260:Female; D005865:Gestational Age; D008297:Male; D009043:Motor Activity / Q000187:drug effects; D009294:Narcotics / Q000633:toxicity*; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D011597:Psychomotor Performance / Q000187:drug effects*; D051381:Rats; D012727:Sex Characteristics
D009294:Narcotics; D003042:Cocaine