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Biomedical subjects

J R Galler

Publications and source records attributed to J R Galler.

At least 55 records · Page 3Linked to original sources
PubMed1991

Prenatal protein malnutrition and hippocampal function: partial reinforcement extinction effect.

Developing rats were either malnourished or well-nourished during the prenatal period by feeding their dams diets of low (6% casein) or adequate (25% casein) protein content 5 weeks prior to mating and throughout pregnancy. All pups were well-nourished from the day of birth onwards. Male offspring aged 107 days were gradually reduced to 80% of their free-feeding weight. When weights were stable they were trained to run in an alley for food rewards given on every trial (continuous reinforcement, CR) or on a random 50% of trials (partial reinforcement, PR), then the running response was extinguished. A very clear and similar partial reinforcement extinction effect (PREE) was demonstrated in the previously malnourished and control rats when reward was discontinued. That is, PR groups showed greater persistence as compared with CR groups. During acquisition, however, differences in running speed were observed in the goal section between 6-25 PR and 25-25 PR groups, and between 6-25 CR and 25-25 CR groups. The latter may be due to differences between the nutritional groups in food motivation.

Analysis of Variance↗
PubMed1991

Prenatal protein malnutrition and maternal behavior in Sprague-Dawley rats.

Female Sprague-Dawley rats were provided with an adequate (25% casein) or low (6% casein) protein diet, fortified with methionine, starting 5 wk prior to gestation and continuing until the birth of their pups. At birth, the offspring were fostered to well-nourished lactating dams as follows: in Experiment 1, litters contained eight prenatally malnourished pups; in Experiment 2, litters consisted of four pups with prenatal malnutrition and four well-nourished pups; control litters for both experiments contained eight well-nourished pups. In Experiment 1, the time spent in passive nursing and pup grooming was significantly higher for dams rearing previously malnourished pups than for those rearing control litters. In Experiment 2, mixed litters were groomed less frequently than control litters, but there was no significant difference between groups for any other measure. In both experiments, the prenatally malnourished pups showed similar body weight deficits relative to well-nourished pups. These findings underscore the usefulness of mixed litters in studying the later effects of prenatal malnutrition because later deficits in brain function are less likely to be attributable to changes in the early rearing environment.

Analysis of Variance↗
PubMed1990

Prenatal protein malnutrition and working memory performance in adult rats.

The performance of prenatally protein malnourished rats was examined in 2 different tasks of learning and memory beginning at 90 or 160 days of age. In Experiment 1, a rewarded alternation task, run as a spatial working memory procedure on an elevated T-maze, revealed no differences between the formerly malnourished (6/25) and control (25/25) rats when either a minimal or a 20-s inter-trial delay was used. Neither was there a difference when an additional, and conflicting, 'information' run was given to provide a source of proactive interference. In extinction, the 6/25 rats required significantly more sessions to abolish their learned alternation response than the controls. In Experiment 2, an operant equivalent of the T-maze task was applied which allowed greater control over the delay interval and task difficulty. Each trial consisted of a forced information response, for which a randomly selected lever was presented, followed by a free-choice stage, when both levers were presented. The rats were rewarded for pressing the lever not presented at the information stage. The inter-trial interval was always 30 s. When the information response requirement was 10 presses no group differences were found in acquisition of the alternation response or in task performance at delays of 5, 10, 15 or 30 s between information and choice stages. As task difficulty was increased, the performance of the 6/25 rats improved more than that of the 25/25 rats, such that they performed significantly better at the longest delay when the information response requirement was 2 presses. This superior performance of the experimental animals is discussed. No differences in reversal were detected. It was concluded that there is no straight-forward 'hippocampal syndrome' in prenatally malnourished adult rats. Working memory appears largely unaffected, whereas susceptibility to interference and extinction may be modified, depending upon the test parameters employed.

Animals↗
PubMed1990

Prenatal protein malnutrition alters response to reward in adult rats.

Developing rats were either malnourished or adequately nourished during the prenatal period by feeding their dams diets of 6% (low) or 25% (adequate) casein content 5 weeks prior to mating and throughout pregnancy. All pups received adequate nutrition from the day of birth onwards. In Experiment 1, male offspring aged 125 days were tested in a food-rewarded variable interval 2-min (VI 2') operant paradigm under three levels of body weight reduction (90%, 85% and 80% of their ad lib feeding weight). Previously malnourished rats showed significantly higher response rates than well-nourished controls at the 90% and 85% levels but not at the 80% level. In Experiment 2, behaviorally native male littermates aged 225 days were tested in a saccharin-solution-rewarded VI 2' operant task. The rate of receipt of reward within each daily session was found to differ in the two nutritional groups. Previously malnourished rats maintained a stable rate of reward throughout the session while the controls showed a rapid decline over the first 15-20 min. The higher rate of reward late in the session in Experiment 2 and the elevated response rate in the first two phases of Experiment 1 suggests that prenatal protein malnutrition increases subsequent responsiveness to reward.

Animals↗
PubMed1990

Fetal protein malnutrition impairs acquisition of a DRL task in adult rats.

Developing rats were either malnourished or adequately nourished during the prenatal period by feeding their dams diets of 6% (low) or 25% (adequate) casein content 5 weeks prior to mating and throughout pregnancy. All pups received adequate nutrition from the day of birth onwards. Beginning at 160 days of age male rats were tested in a DRL-18 sec operant task. It was found that prenatal malnutrition impaired performance during acquisition, though asymptomatic levels were not significantly different. Subsequent limited hold DRL-18 sec schedules in which late as well as early responses went unrewarded indicated that the timing ability of the prenatally malnourished rats was excellent and similar to that of the controls. These late effects of fetal protein malnutrition are discussed in terms of the difficulty in adapting to the change from CRF to DRL-18 sec (possibilities include a reduced ability to develop a timing strategy or increased sensitivity to the change in reinforcement contingencies), while retaining the ability to time responses accurately once the task was acquired.

Animals↗
PubMed1990

The long-term effects of early kwashiorkor compared with marasmus. IV. Performance on the national high school entrance examination.

This is one of a series of studies on the long-term effects of early childhood malnutrition in Barbadian school children. This is the first report of the relationship between early malnutrition and later performance on a national examination administered to all 11-y-old children in Barbados to assign high school seats. We compared scores achieved on the 11-plus examination by 103 boys and girls with histories of marasmus or kwashiorkor with those obtained by 63 healthy comparison children and also with scores obtained by the total island population of children during the same years. We report that children with histories of either type of malnutrition confined to infancy had significantly lower scores on the national high school examination than healthy comparison children. Reduced 11-plus scores were closely associated with teacher reports of attention deficits in the classroom documented when the children were as young as 5 to 8 y of age and also with IQ and academic performance. Early malnutrition had independent effects on performance on the 11-plus examination even when home environmental conditions were controlled for. These findings have important implications for future opportunities available to children with histories of infantile malnutrition.

Barbados↗
PubMed1989

A follow-up study of the influence of early malnutrition on development: behavior at home and at school.

A follow-up study of home and classroom behavior was conducted on 216 children, 9 through 15 years of age, half of whom had histories of moderate-severe protein energy malnutrition (marasmus) during the first year of life. Behavior was measured by two rating scales, administered to teachers and parents of the children. Observations made by teachers and parents were significantly correlated on 33% of the 41 overlapping items in the two questionnaires. The history of malnutrition had a significant association with attention deficits in children up to 15 years reported by parents and teachers, even when the effects of socioeconomic and home environmental factors were controlled. It was concluded that interventions specifically focussed on these attentional deficits should be considered early in life for children exposed to infantile malnutrition in order to prevent behavioral disorders in adolescence.

Adolescent↗
PubMed1988

The influence of early malnutrition on subsequent behavioral development. VII. The effects on maternal depressive symptoms.

A self-rating scale was used to assess the presence or absence of depressive symptoms among mothers of 129 Barbadian school children, ages 5 to 11 years, who had experienced marasmus in the first year of life. They were matched with the same number of mothers of comparison children who had no documented histories of malnutrition. Depressive symptoms, especially feelings of hopelessness, occurred more often among the mothers of previously malnourished children than among mothers of comparison children. Depressive symptoms were also more common in association with disadvantaged socioeconomic and home conditions. Maternal depressive symptoms were significantly correlated with the behavioral and cognitive functioning of the child during the school years. When both nutritional history and environmental conditions were controlled, maternal hopelessness had significant effects on school attendance and grades in reading, but there was no association with IQ. This led us to hypothesize that maternal depressive feelings may be an independent factor contributing to long-term behavioral and cognitive deficits in children with histories of early malnutrition.

Barbados↗
PubMed1985

A follow-up study of the effects of early malnutrition on subsequent development. I. Physical growth and sexual maturation during adolescence.

A follow-up study of growth and development was conducted on 216 Barbadian children aged 9 to 15 yr, half of whom had histories of moderate to severe protein-energy malnutrition in their 1st yr of life. Although index girls had significant delays in sexual maturation and were reduced relative to comparison girls on measures of weight for height, arm circumference, and skinfold thickness, their rate of growth when compared with values obtained 4 yr earlier was equal to or better than that of the comparison group. In contrast, boys in the index group were slightly reduced in height compared with their matched comparisons and had similar patterns of growth and sexual maturation. This study suggests a relationship between an episode of infantile malnutrition and impaired endocrine functioning among girls in the adolescent years.

Adolescent↗
PubMed1985

A follow-up study of the effects of early malnutrition on subsequent development. II. Fine motor skills in adolescence.

One hundred nine children, aged 8 through 15 yr, who suffered from malnutrition in the 1st yr of life and 107 well-nourished comparison children were tested for fine motor skills by the Purdue Pegboard test. The performance of index children was impaired on three of the four test measures. IQ measured concurrently showed a reduction in the index group; when the effects of IQ were eliminated, there was no longer any significant difference between index and comparison groups. The data suggest that the effects of early malnutrition on Pegboard performance are largely mediated by deficits in IQ. The presence of soft neurologic signs measured 4 yr earlier in the same children was highly correlated with reduced Pegboard performance, implying that early malnutrition has effects on nervous system function that are evident at least through 15 yr of age.

Adolescent↗
PubMed1984

The influence of early malnutrition on subsequent behavioral development III. Learning disabilities as a sequel to malnutrition.

The academic performance of 129 Barbadian children (77 boys and 52 girls), who were 5-11-yr-old and suffered moderate to severe protein-energy malnutrition in the first year of life, was compared with the performance of matched comparisons, children who had no history of malnutrition. Children with a history of malnutrition were found to have lower performance on eight out of nine academic subject areas, namely, language arts, mathematics, general science, social science, reading, health, religion, and arts/crafts. Socioeconomic factors in the backgrounds of the children were also examined. A model is presented clarifying the interrelationships of malnutrition, socioeconomic status and school performance. Reduced school performance in the previously malnourished children can be largely accounted for by deficits in classroom behavior, and, to a lesser extent by a reduction in I.Q. Current socioeconomic status is not directly involved in altering academic performance whereas the early history of malnutrition and its accompanying conditions at the time of the illness are leading contributors to altered behavioral outcome and school performance.

Analysis of Variance↗
PubMed1984

The influence of early malnutrition on subsequent behavioral development. IV. Soft neurologic signs.

Soft neurologic signs were evaluated in 101 Barbadian school children, ages 4-11 years, who were malnourished in the first year of life, and 101 comparison children matched for age, sex, and handedness, but who had no history of malnutrition. Previously malnourished children performed significantly slower than comparison children on several timed motor tasks when using the nondominant hand only. Boys were found to perform significantly slower than girls, and younger (4-7 years of age) children performed slower than older (8-11 years of age) children. A model is presented that displays interrelationships among previous malnutrition, soft neurologic signs, classroom behavior, intelligence, and physical growth. In summary, slow motor performance was associated with lower verbal and performance IQ and the presence of attention deficit disorder, as assessed by the child's teacher. The time to perform the motor tests was unrelated to measures of physical growth.

Body Height↗
PubMed1982

Early maternal behaviors predictive of the survival of suckling rats with intergenerational malnutrition.

Mother-pup interactions during the first 12 hours post partum were studied in intergenerationally malnourished and control rats. Pup mortality during the suckling period was found to be associated with nutritional status with only 50% survival in the malnourished series, as compared to 100% survival in the control series. Litters with subsequent high pup mortality were distinguished by abnormal mothering patterns during the first 12 hours of life and reduced pup weight at the end of this period. High pup mortality was associated with increased active nursing, and reductions in passive nursing, pup licking, amount of contact with the pups and time spent in the nest by the lactating female. Thus, the stimulus to active nursing is most intense under conditions where the pups are least likely to survive, whereas the amount of stimulation provided to such pups is reduced. Maximal associations between early mother-pup interactions and subsequent pup weight and survival were present 7-9 hours after birth.

Animal Population Groups↗