Some Effects of Prenatal Zinc Deficiency on Behavior of the Adult Rat

Abstract

ExtractThe effect of zinc deficiency during the latter third of gestation on avoidance conditioning of young adult male rats was compared with the effect of intrauterine starvation and normal pregnancy. Animals which had experienced zinc deficiency avoided shock less well than the offspring of pair-fed control dams. The offspring of pair-fed dams avoided shock less well than animals which were the product of normal pregnancy. Response latencies were inferior in the zincdeficient group, whereas intertrial responses were less on both the previous zinc-deficient and intrauterine starved animals. SpeculationZinc is essential for development of the brain. Fetuses of women who consume inadequate amounts of zinc during pregnancy may be at risk as far as intrauterine brain development and body growth are concerned. Damage caused to such fetuses may be persistent and be mainfest as mental retardation.Zinc is essential for nucleic acid synthesis in the rat (1 8, 19, 23, 25) and protein (8,25) and, therefore, presumably in man. Perhaps becuase of its role in these aspects of metabolism, zinc deficiency has adverse effects on the brain of the fetal (9) and suckling (18) rat. The injury to the brain of the suckling rat is apparently poorly reversible, as behavioral tests of 60-t o 80-day-old rats which have been suckled by zinc-deficient dams until weaning have revealed impaired acquisition of the Tolman Honzig maze (12).The evidence that zinc is essential for muturation of the brain and that zinc deprivation during the critical period of brain growth results in persistent evidence of injury prompted us t o assess the effect of intrauterine zinc deficiency during the third trimester of gestation on subsequent avoidance conditioning of 60-day-old rats. Previous evidence that intrauterine malnutrition can cause persistent behavioral abnormalities in adult rats has been limited (21). MATERIALS AND METHODSTimed pregnant Sprague-Dawley rats were divided into three groups and individually housed in plastic cages with perforated bottoms in a light-and temperature-controlled environment. The dams were purchased timed pregnant from BioLabs (26) and the day of mating was counted as day 0. From the 15th through the 20th day of gestation they were fed a sprayed egg white, biotin-enriched diet containing < 1>0 ppm zinc (13).During this interval two groups served as controls. .One control group (five dams) was pair-fed with the zincdeficient group, while the second control group (five dams) was fed the diet ad libitum. Both control groups were given drinking water containing 50 ppm zinc via an automatic watering device. The zincdeficient group (five dams) were given trace mineral-free water via a central watering device. Before and after the "zinc-deficient interval," all dams were fed a standard laboratory rat chow ad libitum. Food consumption and weight gain of the dams were recorded during pregnancy and lactation. After delivery the number of pups per litter was made approximately equivalent. All litters thus contained 8-10 pups and ...

Environmental Factors in Autism

“…Based on a study of 14,770 individuals aged 3–74 years, the prevalence of Zn 2+ -deficiency in the USA was estimated with 1–3 and 10% of the US population consumes less than half the recommended level for Zn 2+ and thus is at risk for Zn 2+ -deficiency (Tuerk and Fazel, 2009; Wong and Ho, 2012). Moreover, women may not ingest adequate amounts of Zn 2+ during pregnancy (Halas and Sandstead, 1975) and suffer from decreased levels of Zn 2+ during the latter part of pregnancy (Halsted and Smith, 1970; Sandstead, 1973). However, since Zn 2+ -deficiencies can be found in many brain disorders such as schizophrenia and depression (Grabrucker et al, 2011a), more research is needed to investigate the cause of these Zn 2+ -deficiencies.…”

Zinc and the ERK Kinases in the Developing Brain

“…Zinc deficient animals display anorexia, impaired social behavior, increased aggression, anxiety, decreased activity, impaired learning, and memory deficits (Golub et al 1995). To discriminate between the effects of protein/energy malnutrition and zinc deficiency it is often necessary to use pair-fed controls that consume the same amount of food as the zinc deficient animals (Golub et al 1995; Halas et al 1986b; Halas and Sandstead 1975; Keller et al 2001). Compared to pair fed controls, severely zinc deficient dams fail to build a nest, or consume the afterbirth, suggesting an impairment of maternal behavior resulting specifically from zinc deficiency (Apgar 1968).…”

“…Compared to pair-fed animals, young rats fed zinc deficient diets display increased latency on the Morris water maze indicative of spatial memory impairment (Keller et al 2001). While severe zinc deficiency during the last third of gestation also caused lasting memory impairments (active avoidance fear conditioning test and Morris water maze), gestational zinc supplementation improved performance on the Morris water maze (Halas and Sandstead 1975; Tahmasebi Boroujeni et al 2009). Perhaps the most striking findings are the persistence of memory deficits resulting from transient or mild zinc deficiencies.…”

Role of zinc in maternal and child mental health

“…Several studies have reported that zinc deficiency is associated with low levels of activity, lethargy, apathy, and attention in rats and rhesus monkeys (19)(20)(21)(22). These studies fall into 2 categories: 1) those that examined behavioral outcomes after zinc deficiency, and 2) those that assessed the antidepressant-like properties of zinc.…”