Behavioral toxicity chronic effects

Cory-Slechta, D. A. and Thompson, T. (1979). Behavioral toxicity of chronic postweaning lead exposure in the rat. Toxicol. Appl Pharmacol, 41, 151 Cramer, M. B., Johnson, T. D. and Clarke, D. E. (1980). Low-level lead exposure during growth and development absence of behavioral and cholinergic neuromuscular toxicity. Res. Commun. Substance Abuse, 1, 111 Crofton, K. M., Taylor, D. H., Bull, R. J., Sivulka, D. J. and Lutkenhoff, S. D. (1980). Developmental delays in exploration and locomotor activity in male rats exposed to low level lead. Life Scl, 26, 823 Cutler, M. G. (1977). Effects of exposure to lead on social behaviour in the laboratory mouse. Psychopharmacology, 52, 279... 

We have viewed these withdrawal effects on behavior as evidence of behavioral dependence on PCP. Behavioral signs have also been reported in human users of PCP during withdrawal (Tennant et al. 1981) however, these instances appear to be relatively rare. Nonetheless, the relative ease with which a dependence phenomenon can be produced in monkeys suggests that PCP has a potential for producing dependence in PCP users, particularly those who use the drug very frequently. Behavioral sequelae seen in chronic PCP abusers might be examined as possible manifestations of dependence as well as of cumulative toxicity. 

Grant LD, Kimmel CA, West GL, et al. 1980. Chronic low-level lead toxicity in the rat II. Effects on postnatal physical and behavioral development. Toxicol Appl Pharmacol 56 42-58. 

Depending on the time of drug exposure, the type of scientific information desired, and the necessity of behavioral correlations, a researcher can perform acute and/or chronic EEG experiments. Limitations of the former are that most drugs that produce general anesthesia modify the pattern of EEG activity and thus can complicate subtle effects of toxicants. However, this limitation can be partially avoided if the effect is robust enough. For sleep-wakefulness studies, it is also essential to monitor and record the electromyogram (EMG). 

Toxicologists nowadays take a broad view of developmental toxicity they consider not only structural but also functional abnormalities to qualify as adverse, as long as they were produced as a result of exposures incurred in utero. Thus, for example, the developmental effects of chronic alcohol abuse by pregnant women, known as fetal alcohol syndrome (FAS), are characterized not only by the presence of certain craniofacial abnormalities, but also by a variety of disabilities such as shortened attention span, speech disorders, and restlessness. Although fully expressed physical deformities included in FAS are associated with heavy drinking, debate continues on the level of alcohol consumption, if any, that is without these more subtle effects on behavior. 

Cigarette characteristics that influence nicotine delivery to the smoker (including nicotine and ammonium content in tobacco filler) as well as human smoking behavior, deserve special consideration, because nicotine causes and maintains addiction that leads to chronic exposure to a chemical toxicant with known harmful health effects, including cancer (UDHHS 2004 lARC 2004 2007). 

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