Operant behavior of rats exposed before or after weaning to low levels of lead

Thesis/Dissertation · Sun Jan 01 04:00:00 EST 1978

DOI:https://doi.org/10.2172/5997817· OSTI ID:5997817

Angell, Norman F. ^[1]

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1. Univ. of Rochester, NY (United States)

Rats were exposed to lead under one of three conditions. One group received lead by suckling dams who had their drinking water replaced with a solution of 0.2% lead acetate. A second group was placed on the same concentration of lead-treated drinking water at weaning. A third group received both pre-weaning and postweaning treatments. Behavioral testing was begun of day 58. The median blood lead concentration at weaning was 100 μg percent. On day 133, the blood lead concentrations of the two groups exposed postweaning were 65 μg percent while the preweaning group had dropped to 9 μg percent. The only overt signs of lead exposure occurred in the group exposed both preweaning and postweaning. This group showed a slight retardation of growth between weaning and day 54 of life. These low levels of lead exposure produced subtle alterations in behavior. The two groups exposed post-weaning showed a statistically significant lengthening of the median interresponse time. In the ratio size manipulation, the control group showed an approximately linear trend when ratio size was plotted against time to the first response in the ratio. No such trend was evident in the lead exposed groups. The results of this study lead to the speculation that low blood lead concentrations produce increases in response rate, while higher blood lead concentrations result in lowered response rates. Behavioral, neuropathological, and neurochemical evidence is consistent with the hypothesis that lead produces behavioral effects by interfering with dopaminergic neurotransmission. The results indicate that current standards of 40 μg percent for children may be too high. Such lead concentrations could produce behavioral damage with serious, long-term consequences.

• Research Organization: Univ. of Rochester, NY (United States). Dept. of Radiation Biology and Biophysics
• Sponsoring Organization: USDOE
• DOE Contract Number: EY-76-C-02-3490
• OSTI ID: 5997817
• Report Number(s): UR--3490-1533
• Country of Publication: United States
• Language: English

Related Subjects

550100 -- Behavioral Biology
551000 -- Physiological Systems
560305* -- Chemicals Metabolism & Toxicology-- Vertebrates-- (-1987)
59 BASIC BIOLOGICAL SCIENCES
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMALS
BEHAVIOR
BIOLOGICAL EFFECTS
CHRONIC EXPOSURE
DATA
DATA FORMS
DISEASES
ELEMENTS
EXPERIMENTAL DATA
INFORMATION
INGESTION
INTAKE
ISOLATED VALUES
JUVENILES
LEAD
MAMMALS
METALS
NUMERICAL DATA
PATHOLOGICAL CHANGES
RATS
RODENTS
VERTEBRATES