PMID- 12798963
OWN - NLM
STAT- MEDLINE
DCOM- 20030728
LR  - 20191210
IS  - 0892-0362 (Print)
IS  - 0892-0362 (Linking)
VI  - 25
IP  - 4
DP  - 2003 Jul-Aug
TI  - Effects of perinatal exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin on spatial 
      and visual reversal learning in rats.
PG  - 459-71
AB  - 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is a ubiquitous environmental 
      contaminant that has been shown to alter spatial and visual learning following 
      developmental exposure. The current study examined the effects of gestational and 
      lactational exposure to TCDD on spatial and visual discrimination/reversal 
      learning (spatial and visual RL) in rats using two-lever operant testing 
      chambers. Pregnant Sprague-Dawley rats (10 per dose) received either 0 or 0.1 
      microg/kg TCDD per orem in corn oil from gestational day (GD) 10 to GD 16. One 
      male and one female from each litter were tested beginning at 100 days of age. 
      For spatial RL, animals were reinforced for pressing the lever associated with 
      the correct spatial location (either left or right). For visual RL, the animals 
      were reinforced for pressing the lever associated with the correct visual 
      stimulus (either the illuminated or nonilluminated cuelight). After reaching 85% 
      correct for two consecutive days, the opposite spatial location or visual cue was 
      reinforced. Five reversals were conducted for spatial RL, and two reversals for 
      visual RL. For spatial RL, there were no differences between the TCDD-exposed and 
      control rats in total number of errors committed. However, an in-depth analysis 
      of errors in four different phases of the learning process revealed that 
      TCDD-exposed rats made more errors early in learning when they were just 
      beginning to learn the new reinforcement contingencies. The importance of this 
      increase in errors during the initial stage of learning is unclear, given that 
      there was no increase in overall errors to criterion. For visual RL, there was a 
      reduction in errors on original learning (OL) for TCDD-exposed males, while 
      TCDD-exposed females exhibited a reduction in errors on the second reversal. 
      Subsequent response pattern analyses revealed that the facilitation in 
      performance was due to a more rapid transition through the early phase of 
      learning. Why males were improved on OL and females were not until the second 
      reversal is unknown, but the different patterns could reflect differences in 
      learning style in male and female rats. In keeping with previous research, the 
      results of the current study underscore the fact that (1) alterations in 
      cognitive function observed following early TCDD exposure are very subtle and (2) 
      under some conditions, learning is actually facilitated, rather than impaired, in 
      TCDD-exposed animals.
FAU - Widholm, John J
AU  - Widholm JJ
AD  - Department of Veterinary Biosciences, College of Veterinary Medicine, University 
      of Illinois at Urbana-Champaign, 2001 South Lincoln Avenue, Urbana, IL 61802, 
      USA. jwidholm@uiuc.edu
FAU - Seo, Byung Woun
AU  - Seo BW
FAU - Strupp, Barbara J
AU  - Strupp BJ
FAU - Seegal, Richard F
AU  - Seegal RF
FAU - Schantz, Susan L
AU  - Schantz SL
LA  - eng
GR  - F32 ES05885/ES/NIEHS NIH HHS/United States
GR  - R01 ES07921/ES/NIEHS NIH HHS/United States
PT  - Comparative Study
PT  - Journal Article
PT  - Research Support, U.S. Gov't, Non-P.H.S.
PT  - Research Support, U.S. Gov't, P.H.S.
PL  - United States
TA  - Neurotoxicol Teratol
JT  - Neurotoxicology and teratology
JID - 8709538
RN  - 0 (Environmental Pollutants)
RN  - 0 (Polychlorinated Dibenzodioxins)
SB  - IM
MH  - Analysis of Variance
MH  - Animals
MH  - Behavior, Animal
MH  - Case-Control Studies
MH  - Discrimination, Psychological/drug effects
MH  - Environmental Pollutants/*toxicity
MH  - Female
MH  - Male
MH  - Polychlorinated Dibenzodioxins/*toxicity
MH  - Pregnancy
MH  - *Prenatal Exposure Delayed Effects
MH  - Psychomotor Performance/drug effects
MH  - Rats
MH  - Rats, Sprague-Dawley
MH  - Reaction Time
MH  - Reversal Learning/*drug effects
MH  - Sex Characteristics
MH  - Spatial Behavior/*drug effects
MH  - Visual Perception/drug effects
EDAT- 2003/06/12 05:00
MHDA- 2003/07/29 05:00
CRDT- 2003/06/12 05:00
PHST- 2003/06/12 05:00 [pubmed]
PHST- 2003/07/29 05:00 [medline]
PHST- 2003/06/12 05:00 [entrez]
AID - S089203620300014X [pii]
AID - 10.1016/s0892-0362(03)00014-x [doi]
PST - ppublish
SO  - Neurotoxicol Teratol. 2003 Jul-Aug;25(4):459-71. doi: 
      10.1016/s0892-0362(03)00014-x.