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J R Galler

Publications and source records attributed to J R Galler.

At least 73 records · Page 4Linked to original sources

Visual discrimination in rats: the effects of rehabilitation following intergenerational malnutrition.

The effect of rehabilitation following intergenerational malnutrition in rats was observed using 3 tests of visual discrimination (Lashley tests). The following groups were studied at 3 months of age: animals nutritionally deprived of protein for many generations (intergenerational malnutrition), those from the same stock rehabilitated for 1 to 2 generations at an adequate protein level, and controls from a stock never exposed to malnutrition. Males rehabilitated for 2 generations showed some improvement in performance in the Lashley tests, but did not attain the level of well-nourished controls. In agreement with the earlier data, females were less susceptible to behavioral deficits from intergenerational malnutrition and recovery was observed after 1 generation of rehabilitation. Growth of both males and females rehabilitated for 1 or 2 generations was superior to that of control rats.

Animals↗

Home-orienting behavior in rat pups: the effect of 2 and 3 generations of rehabilitation following intergenerational malnutrition.

In an earlier study in this laboratory, we examined home-orienting ability in rats with histories of intergenerational malnutrition that were rehabilitated postnatally with an adequate protein diet (Galler, 1979). Despite increased size and activity, 1st-generation rehabilitated pups showed no improvement in homing ability when compared to malnourished pups. In the current study, offspring of rats with intergenerational malnutrition were rehabilitated for 2 additional generations and tested for homing ability from postnatal Day 4 through Day 12. The pups rehabilitated for 2 and 3 generations did not perform as well as control pups, even though growth and activity returned to normal levels. Furthermore, the rehabilitated pups failed to demonstrate any preference for the nest on all days of testing; in contrast, control pups favored the nest quadrant by Day 8 of life. No significant improvement was evident on any measure from the 2nd to the 3rd generation of rehabilitation.

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Reproductive performance in rats with different histories of malnutrition.

1. Reproductive competence, as measured by weight gain during pregnancy, duration of pregnancy and foetal outcome, was assessed in primiparous rats (4--6 months of age) with various histories of malnutrition. 2. Although weight gain during pregnancy was reduced in rats with intergenerational malnutrition, the duration of pregnancy and number of live births did not differ from well-fed controls, suggesting adaptation of these measures to long-term dietary deprivation. 3. Rats malnourished from birth through pregnancy (one generation of malnutrition) had fewer live births than did rats with chronic, intergenerational malnutrition or well-fed controls rats. 4. Gestation was prolonged and weight gain accelerated among female rats with histories of intergenerational malnutrition, who had been provided with an adequate diet from birth through pregnancy.

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Maternal behavior following rehabilitation of rats with intergenerational malnutrition. 1. Persistent changes in lactation-related behaviors.

Female rats rehabilitated for one or two generations on an adequate level of dietary protein following a history of intergenerational malnutrition were studied during the postnatal suckling period. No recovery occurred after two generations of dietary rehabilitation for most measures of maternal behavior including active nursing, passive nursing, pup-oriented behavior, time spent in the nest or time spent in contact with the young. In contrast, nest quality improved to normal levels after rehabilitation. In addition, growth of pups born to females rehabilitated for one generation was similar to growth of control pups, and in the case of mothers rehabilitated for two generations, growth of offspring exceeded that of the control pups. These results demonstrate variable sensitivity of different maternal behaviors to rehabilitation following a history of intergenerational malnutrition, with lack of normalization of a considerable number of maternal behaviors. Consequently, some of these abnormalities in maternal behavior may result in persistent abnormalities in the behavior of offspring over several generations.

Age Factors↗

Maternal behavior following rehabilitation of rats with intergenerational malnutrition. 2. Contribution of mothers and pups to deficits in lactation-related behaviors.

In a companion paper, we reported the persistence of an increase in active nursing and nursing-related behaviors in rats that were rehabilitated following prolonged intergenerational malnutrition. The rehabilitated litters contained females and pups fed an adequate diet for up to three generations after a history of malnutrition. In the current study, a 2 X 2 cross-over design was used during the lactation period in which rehabilitated mothers suckled rehabilitated pups or well-nourished control pups, and control mothers similarly suckled rehabilitated or control pups. We found that maternal factors were dominant in determining the amount of active nursing, and that pup factors modified the maternal influence on other lactation-related behaviors.

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Gender differences in visual discrimination by rats in response to malnutrition of varying durations.

Visual discrimination of hooded rats was tested at 3 months of age by a Lashley procedure. Three groups of rats were used: those with histories of protein deprivation for up to 20 generations, those with protein deprivation for a single generation, and well-nourished controls. Growth retardation was present to a similar degree in both genders of the 2 malnourished groups. Deficits in visual discrimination were observed in female animals with intergenerational malnutrition, but not in females with single-generation malnutrition. Males with intergenerational and single-generation malnutrition showed equal deficits in visual discrimination. These findings demonstrate that the performance of female rats is impaired only after prolonged exposure to malnutrition, whereas males are vulnerable after shorter periods.

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Home-orienting behavior in rat pups surviving postnatal or intergenerational malnutrition.

Growth and home-orienting behavior were studied during the 1st 12 days of life in 3 groups of rat pups: (1) those with intergenerational malnutrition; (2) those with postnatal malnutrition produced by cross-fostering pups born of well-nourished mothers to lactating females maintained on a low-protein diet; and (3) well-nourished control pups. Growth of pups was impaired in both malnourished groups, and eye-opening was similarly delayed. On tests of homing behavior, both malnourished groups were impaired to a similar extent and were less likely to find their way to the nest than were control pups. However, survival rates were significantly lower (50%) in the postnatally malnourished group but not in the intergenerationally malnourished group (73%), as compared with controls (100%). These findings suggest that adaptation occurs in long-term malnutrition with increased survival. However, physical characteristics and homing behavior in early life are not distinguishable in those surviving short- or long-term malnutrition. This is in contrast to the finding of more severe behavioral deficits in later life among rats subjected to many generations of malnutrition than among those malnourished for only 1 generation.

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Varying deficits in visual discrimination performance associated with different forms of malnutrition in rats.

Visual discrimination at 3 months of age was examined by the Lashley jumping stand test to rats malnourished by one of the following techniques: intergenerational malnutrition over 14 to 18 generations; protein deficiency from birth on; rearing in large litters, and rotation among lactating and non-lactating females. All four treatments caused stunting during the litter period, but only the first two were associated with reduced weights at the time of testing. Deficits in visual discrimination were most severe in males and females with intergenerational malnutrition. Both large-litter rearing and protein deficiency for one generation impaired visual discrimination in males only, whereas rotation between lactating and non-lactating females did not reduce visual discrimination in either gender. It is possible that extranutritional factors associated with each type of malnutrition may serve either to enhance or diminish the impact of malnutrition on the nervous system.

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Home orientation in nursling rats: the effects of rehabilitation following intergenerational malnutrition.

Rat pups with histories of intergenerational malnutrition were rehabilitated by cross-fostering at birth to well-nourished females. These pups weighed slightly less than well-nourished controls but significantly more than pups reared by malnourished females. Rehabilitated and control pups were both more active than malnourished pups reared by malnourished females. However, the percentage of nest returns by pups displaced to other parts of the cage was low among rehabilitated pups as compared with controls, but did not differ from that of pups with histories of intergenerational malnutrition reared by malnourished females. These data suggest that, although activity is a product of postnatal condition, home-orienting behavior is affected by a history of intergenerational malnutrition regardless of rehabilitation.

Animal Population Groups↗

Ulcerative dermatitis in rats with over fifteen generations of protein malnutrition.

1. Male and female rats with histories of up to twenty generations of protein malnutrition were found to be at a higher risk for the development of ulcerative dermatitis than rats maintained on a low-protein diet for one generation or in controls on an adequate-protein intake. 2. In all groups, female rats were more likely to have dermatitis than male rats. 3. Bacteriologic examination was performed in the intergenerationally malnourished and control animals; Staphylococcus aureus was isolated from the skins of animals in both groups, whether or not any lesion was present. In these two groups of animals, experimental inoculation with S. aureus produced dermatitis only in the malnourished animals.

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Motor competence in rats of different stocks reared in large and small litters.

The effects of sex and stock on a task of motor competence (balancing on a rod) were studied in Long-Evans, Sprague-Dawley and Wistar rats reared in large and small litters. The data indicated significant sex and stock effects but no effects of rearing condition. Although no nutritional effect was found on this task, the data suggest that stock differences should receive greater attention particularly with regard to the possibilities that such differences provide for the identification and analysis of a broad spectrum of effects.

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Use of partial mammectomy to produce malnutrition in the rat.

Partial mammectomy in the Sprague-Dawley rat was studied as a method for producing malnutrition without accompanying differences in litter size. Throughout the litter period, experimental litters weighed less than controls. No difference in the rate of development of various anatomical landmarks was noted with this degree of malnutrition. Maternal behavior in the nursing dam was measured with respect to nursing, nesting, and retrieval behavior. Mammectomized subjects built and maintained better nests and spent more time in a nursing posture, but were less likely to retrieve their litter than were control animals. At weaning the intact mammae of the experimental animals were larger than those of control animals.

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Variability of the effects of rearing in a large litter on the development of the rat.

The variability in the effects of rearing rats in large litters was examined. Subjects reared in litters of 16 were stunted and delayed in the appearance of eye-opening and fur-eruption as compared with pups reared in litters of 8. However, the effects of the large-litter treatment were not uniform; pups in this group exhibited markedly higher variability with regard to all measures than did pups from small litters. In fact, some pups from the large litters were heavier and some exhibited developmental landmarks earlier than did most pups reared in small litters.

Age Factors↗

The effects of cocaine exposure prior to and during pregnancy in rats fed low or adequate protein diets.

Sprague-Dawley rats were fed a diet of low protein content (6% casein), an isocaloric diet of adequate protein content (25% casein), or a laboratory chow diet for 5 weeks prior to mating and throughout pregnancy. Within each diet group, rats received either cocaine (30 mg/kg IP two times per week prior to mating and 30 mg/kg or 40 mg/kg SC daily from days 3 to 18 of pregnancy) or saline injections. Cocaine produced a greater reduction in food intake during pregnancy in the malnourished group compared with the other two diet groups. The effect of cocaine on food intake was minimal in chow-fed rats. Weight gain in pregnancy was reduced by cocaine in a dose-dependent manner, and by malnutrition. Both prenatal cocaine and malnutrition impaired skeletal maturation of the pups, but there was no additive effect of the two insults on this measure. Litter size was significantly reduced by the 40 mg/kg, but not by the 30 mg/kg dose of cocaine across all diet groups. Consequently, the 40 mg/kg dose of cocaine proved to be fetotoxic in this model. Birth weight was significantly reduced by prenatal malnutrition but not by prenatal cocaine. Gestation length was unaffected by either insult. Hence, the ability to detect a diet x drug interaction was dependent upon the variable being measured.

Analysis of Variance↗