title: The spatial learning and memory performance in methamphetamine-sensitized and withdrawn rats.
abstract: OBJECTIVE
  There is controversial evidence about the effect of methamphetamine (METH) on spatial memory. We tested the time- dependent effects of METH on spatial short-term (working) and long-term (reference) memory in METH -sensitized and withdrawn rats in the Morris water maze.
  
  
  METHODS
  Rats were sensitized to METH (2 mg/kg, daily/5 days, SC). Rats were trained in water maze (4 trials/day/for 5 days). Probe test was performed 24 hr after training. Two days after probe test, working memory training (2 trials/day/for 5 days) was conducted. Acquisition-retention interval was 75 min. The treatment was continued per day 30 and 120 min before the test. Two groups of METH -sensitized rats were trained in reference memory after a longer period of withdrawal (30 days).
  
  
  RESULTS
  Sensitized rats exhibited significantly longer escape latencies on the training, spent significantly less time in the target zone (all, P<0.05), and their working memory impaired 30 min after injection. While, METH has no effect on the spatial learning process 120 min after injection, and rats spent significantly less time in the target zone (P<0.05), as well it has no effect on working memory. Also, impairment of reference memory persisted after prolonged abstinence.
  
  
  CONCLUSIONS
  Our findings indicated that METH impaired spatial learning and memory 30 min after injection, but spared spatial learning, either acquisition or retention of spatial working, but partially impaired retention of spatial reference memory following 120 min after injection in sensitized rats, which persisted even after prolonged abstinence.
authors.affiliation: Faculty of Psychology and Educational Sciences, University of Semnan, Semnan, Iran.
authors.forename: Imanollah
authors.initials: I
authors.lastname: Bigdeli
authors.affiliation: Faculty of Psychology and Educational Sciences, University of Semnan, Semnan, Iran.
authors.forename: Masomeh Nikfarjam-Haft
authors.initials: MN
authors.lastname: Asia
authors.affiliation: Laboratory of Animal Addiction Models, Research Center and Department of Physiology, School of Medicine, Semnan University of Medical Sciences, Semnan, Iran.
authors.forename: Hossein
authors.initials: H
authors.lastname: Miladi-Gorji
authors.affiliation: Faculty of Psychology and Educational Sciences, University of Semnan, Semnan, Iran.
authors.forename: Atefeh
authors.initials: A
authors.lastname: Fadaei
keywords: Long -term memory; METH- sensitized rats; Short -term memory; Spatial memory