bluuebunny/crossref_metadata_2025_split huggingface dataset:
Behavioral and neuroendocrine effects in rats of postnatal exposure to low dietary levels of maneb
Authors: Sobotka Thomas J. , Brodie Robert E. , Cook Michelle P. 
Published: January 2005

AbstractSeveral behavioral and neurochemical consequences of neonatal and/or postneonatal exposure to maneb (ethylenebisdithiocarbamate manganese), a popularly used fungicide, were investigated in male rats at dietary levels of 0, .5, 1.0, or 10 ppm. Three different periods of exposure were employed: (1) during the 28‐day neonatal period; (2) during the 5 months postweaning; and (3) during both the neonatal and postweaning periods of life. Behaviorally, neonatal exposure to maneb depressed exploratory activity of the 30‐day old wealings. As adults, neonatally treated rats demonstrated enhanced learning ability in an operant conditioning procedure. However, no facilitation of learning was found in animals whose exposure to maneb was restricted to only their postweaning period of life. Although unrelated to the behavioral changes, neuroendocrine effects were also found. Regional brain cholinesterase (ChE) activity was reduced in rats exposed to maneb during either the neonatal period alone or during the 5 month postweaning period alone, but continuous exposure to maneb during both the neonatal and postweaning periods did not appreciably affect brain ChE activity. Adult plasma corticosterone levels were elevated by exposure to maneb only postweaning. No such change was found in the neonatally exposed rats.
Visual discrimination learning of the young chick: Key‐peck conditioning with heat‐light reinforcement
Authors: Zolman James F. , Chandler Sharon D. , Black Diane 
Published: January 2005

AbstractHeat‐light reinforcement procedures are described which were developed for key‐peck conditioning of 1‐day‐old chicks. 24 Vantress x Arbor Acre and 24 White Leghorn chicks were randomly assigned to two preference conditions in a successive discrimination problem: bright yellow as S+ and dim blue as S−, or the reverse. During 7 sessions of 48 discrete conditioning trials each, the chicks learned quickly to peck the key when the S+ was presented and to inhibit pecks when the S− was presented. This differential responding to S+ and S− was evident when the chicks were 1 day old (sessions 1 and 2) and became more evident with further training when the chicks were 2 days old (sessions 3–7). There were no significant preference or breed differences. Contrary to previous results, this experiment demonstrated that neural mechanisms involved in inhibition of responses are well developed in the young chick.
Effects of prenatal maternal handling and rearing with aunts on behavior, brain weight, and whole‐brain serotonin levels
Authors: Plaut S. Michael , Graham Charles W. , Leiner Katharine Y. 
Published: January 2005

AbstractRats were handled daily throughtout gestation. Their litters and those of nonhandled rats were fostered to nonhandled mothers, half of whom were then housed with a virgin female (aunt). Prenatal handling decreased serotonin levels in 21‐day‐old offspring tested at the trough of the 24‐hr serotonin rhythm. Rearing with aunts resulted in lower brain weights among males, but had no effect on the serotonin levels of weanling rats. Both prenatal handling and rearing with aunts affected scores of female offspring in a reaction‐to‐handling test administered at age 56 days, but an open‐field test yielded only sex differences. Rearing with aunts differentially affected trough serotonin levels at that age, males showing a signficant decrease, whereas female values increased.
Latency of EEG attenuation (“blocking”) in relation to age and reaction time in normal children
Authors: Surwillo Walter W. 
Published: January 2005

AbstractBlocking latency of the EEG (BL) and reaction time (RT) were investigated in 53 normal boys aged 88–207 months. The purpose was to discover whether changes in BL which have been reported to occur during growth in children parallel the well known decrease in RT that accompanies development. EEGs were recorded (1) during an experiment in which the tracings were attenuated by short, high intensity flashes of white light, and, (2) while the subjects performed an auditory reaction task in which they responded to a tone that occurred without warning by closing a switch as quickly as possible.As expected, findings showed an inverse relationship between RT and age of substantial magnitude (r= −.822). By contrast, no relationship was apparent between BL and age in the group tested. This finding, together with the fact that the correlation between BL and RT was not significantly different from zero, suggested that BL and RT follow different developmental courses and may be measures of essentially independent systems in children 7 years and older.
The effects of saline or blank injections during development on maze learning at maturity
Authors: Stein Donald G. 
Published: January 2005

AbstractRats were given daily isotonic saline or blank injections intraperitoneally during one of three postnatal periods (1–25 days, 25–50 days, 50–75 days) and were then subjected to 18 Hebb‐Williams maze problems beginning at 92 days of age. The rats receiving the blank injections from 25–50 days of age were impaired on later maze performance. Weight differences did not correspond to the effects of the control injections.
Age effects in the acquisition and retention of active and passive avoidance learning by rats
Authors: Egger Garry J. , Livesey Peter J. 
Published: January 2005

AbstractThree groups of 8 male albino rats within each of the age ranges 24, 50, and 100 days were trained on an active avoidance task to a criterion of 10 successive avoidances. The number of trials to criterion was found to be a monotonic function of age. One group at each age was tested immediately thereafter for passive avoidance of the conditioning chamber, another group was tested for passive avoidance after 25 days, and the third was tested for retention of active avoidance after 25 days. Groups at 50, 75, and 125 days were used as controls for the active avoidance retention groups. All animals took significantly fewer trials to relearn the active avoidance after 25 days than did controls on the acquisition of the original learning task. On passive avoidance 24‐day olds performed less efficiently than the older groups and failed to show any retention after 25 days.
Ultrasounds and maternal behavior in small rodents
Authors: Noirot Eliane 
Published: January 2005

AbstractRodent pups in distress emit 2 different types of ultrasonic calls. One is given in response to cold; the other in response to unusual tactile stimulation. The effects of these calls on adult behavior can also be classified into 2 categories. Some exert positive effects attracting the adult to the pup in distress and stimulating searching, retrieving, and nest‐building. Others cause withdrawal of the adult from the pup thereby causing cesation of rough handling or aggression. The ultrasounds elicited by cold could exert the positive effects whereas those elicited by tactile stimulation produce the withdrawal effects.
Mice reared with rats: Effects of prenatal and postnatal maternal environments upon hybrid offspring of C57BL/10J and Swiss Albino mice
Authors: Denenberg Victor H. , Paschke Richard E. , Zarrow M. X. 
Published: January 2005

AbstractThe hybrid offspring of reciprocal crosses between C57BL/10J and Swiss Albino mice were fostered at birth to Swiss Albino mouse mothers or to Purdue‐Wistar rat mothers.Measures were taken of incidence of survival, body weight, open‐field performance, passive avoidance learning, and fighting. As compared to mice reared by mouse mothers after birth, mice reared by rat mothers (a) had a lower incidence of survival at weaning; (b) weighed more; (c) were less active in the open field, defecated less in the field, and had a greater latency to initiate movement in the field; and (d) had poorer passive learning scores. The findings indicate that the postnatal maternal environment has pervasive effects upon a number of behavioral and morphological characters, but reveal a minimal effect of the prenatal environment. Moreover, they indicate that the absence of differences in fighting scores among the 4 groups may be caused by dominant genes.
The effects of infantile stimulation and intermittent fasting and feeding on life span in the black‐hooded rat
Authors: Kendrick Don C. 
Published: January 2005

AbstractThe effects of accelerating development by 2 kinds of infantile stimulation (handling or faradic stimulation) interacting with a postweaning intermittent fasting and feeding regime have been assessed in relation to changes in life span. The results indicate that the fasting regime significantly increases life span in those animals subjected to infantile stimulation. Some of the claims made concerning the secondary effects of intermittent fasting on excitability levels of the central nervous system were not supported.
The interaction of genotype and exogenous neonatal androgen and estrogen: Sex behavior in female mice
Authors: Vale Jack R. , Ray Donald , Vale Carol A. 
Published: January 2005

AbstractFemale neonates of the A, BALB/c, and C57BL/6 mouse strains were injected with androgen, estrogen, or oil and the effects upon their sex behavior studied. Genotype and treatment combined interactively on a substantial number of variables, indicating that the effects of perinatally administered sex hormones and genotype cannot be considered separately. Effects of the 2 hormones were often in different directions. The lordosis response of one genotype appeared relatively insensitive to neonatal treatment, particularly with androgen.
Behavioral development in mice selected for differences in brain weight
Authors: Fuller John L. , Geils Helen D. 
Published: January 2005

AbstractMouse pups from the SEL‐16 lines which have been selected for high or low brain weight differed from unselected controls in body size and intensity of some behaviors, particularly between 4 and 10 days of age. The differences were not related in a simple manner to brain size nor to brain growth patterns previously described by the authors. A hypothesis of pleiotropic effects of “brain weight genes” upon behavior is not supported by the data.
Transient and enduring effects of handling on infant and maternal behavior in mice
Authors: Sherrod Kathryn B. , Connor William H. , Meier Gilbert W. 
Published: January 2005

AbstractEffects of handling on both maternal and infant behavior were observed daily on laboratory mice from birth to weaning. Pups were cross‐fostered after 7 days in order to assess enduring effects of handling on mothers and infants separately. The handling manipulation resulted in increases in maternal behavior which were stimulating to pups during the first 7 postpartum days. However these effects dissipated sometime during the 24‐hr period between observations, as handled litters observed prior to the handling manipulation did not differ from unhandled litters, and neither maternal nor infant effects of handling were significant, following cross‐fostering.
Sexual behavior of male rats following removal of the glans penis at weaning
Authors: Spaulding William D. , Peck Carol K. 
Published: January 2005

AbstractMale rats in which the glans penis was removed at 20 days of age showed all of the sexual behavior patterns of normal rats, including ejaculation, when tested as adults. However, the distribution of the behaviors within the patterns was statistically different from normal: the experimental males required a greater number of mounts and a longer time for ejaculation than did control males.
The development and behavioral characteristics of the startle response in the zebra fish
Authors: Kimmel Charles B. , Patterson Jill , Kimmel Richard O. 
Published: January 2005

AbstractThe behavioral responses of developing larvae of the zebra fish (Brachydanio rerio) to vibratory stimulation are described. Larvae begin to respond after 4‐5 days from the time of fertilization (the approximate time of hatching). Once this response appears, the characteristic movement, the latency of the response, and the sensitivity of the larva to sound do not change for a period of several days. A number of related behavioral changes are observed at the same time the response to sound appears.The larval startle response is a characteristic pronounced tail flip. It is very similar to the adult startle response which is believed to be mediated via Mauthner's neuron. The data suggest that the usual response may be due to a wave of muscular contractions along one side of the larva, as would be expected to result from an action potential in a Mauthner cell. More complex responses were also observed and are described.
Effects of maternal undernutrition on offspring behavior: Incentive value of a food reward and ability to escape from water
Authors: Cravens Richard W. 
Published: January 2005

AbstractTwo experiments were performed to evaluate the effects of maternal undernutrition during gestation and lactation upon the incentive value of a food reward and upon performance and reversal learning in an escape‐from‐water task. The results of the present experiments suggest that offspring of underfed mothers have lower incentive values for food rewards than control offspring, although they are able to perform comparably in an escape‐from‐water task. The implication is that the results of hunger‐motivated tests of problem solving or learning in maternally undernourished and control offspring are suspect.
Early experience, emotionality, and exploration in the rat: A critique of Whimbey and Denenberg's hypothesis
Authors: Aitken P. P. 
Published: January 2005

AbstractWhimbey and Denenberg have suggested that emotionality and exploration are orthogonal or independent dimensions of behavior which can be affected to different degrees by stimulation during infancy. This paper suggests that the factorial structure of the data on which they based this hypothesis supports the viewpoint that the relationship between measures of fearfulness and exploration is inverse.
Some aspects of the behavior of young and adult rats treated with p‐chlorophenylalanine in infancy
Authors: Adlard B. P. F. , Smart J. L. 
Published: January 2005

AbstractSuckling rats were treated with p‐chlorophenylalanine (PCP; 300 mg/kg, 5–15 days of age or 150 mg/kg, 5–21 days) in order to selectively deplete brain 5‐hydroxytryptamine (5HT). Some bodily growth retardation occurred during treatment. Although a normal body weight was achieved in adulthood, some stunting of cerebellar growth had occurred.During PCP treatment a reduction in State 2 (paradoxical) sleep occurred at 10 and 14 days of age, without alteration in total sleeping time. Compared with controls, locomotor activity in the open field was reduced only at 22 days of age after prolonged treatment. A marked reduction in turning frequency was evident at 12 and 18 days.Passive‐avoidance behavior was facilitated when tested 4–6 days after cessation of PCP. This may represent increased reactivity to a noxious stimulus and is probably dependent on concomitant cerebral 5HT depletion.In adults who received PCP in infancy, brain 5HT concentraton was normal. Learning ability as assessed in the Hebb‐Williams maze and passive avoidance in adulthood were not affected. However, a significant degree of hyperactivity was observed in open‐field tests.
The effects of lifelong isolation on species identification in zebra fish (Brachydanio rerio)
Authors: Mc Cann Lee I. , Matthews James J. 
Published: January 2005

AbstractVirtually no information is currently available regarding the relative effects of innate and experiential factors on the development of species identification in fish. Those studies which have approached the problem through schooling behavior have confounded species identification with attraction to a single available school of species‐mates. In this study, isolated Brachydanio rerio spent significantly less time in nonpolarized schools with species‐mates than controls when animals of a related species were available as an alternative. This difference suggests the involvement of experiential factors in species identification and questions the assumption that species identification is entirely innate.
Learning and retention of a discriminated escape response in infant mice
Authors: Nagy Z. Michael , Murphy James M. 
Published: January 2005

AbstractSeparate groups of mice received 25 training trials in a shock‐escape T‐maze at 7,9,11, or 13 days of age, followed by retention trials 24 hr later. During original training, all mice were trained to the goal opposite their 1st‐trial choice‐point turn. During the retraining sessions, half of the mice in each age group received an additional 25 trials to the same goal as original training, while the other half was trained to the goal opposite that of original training. All age groups demonstrated improved performance during training in reaching the choice point, although only mice 9 days of age and older indicated an increase in correct choice‐point turns. During retraining, only the groups trained at 11 and 13 days of age showed significant effects of prior training.
Activity and exploratory behavior of adult offspring of undernourished mother rats
Authors: Smart J. L. 
Published: January 2005

AbstractMother rats were either adequately fed or were undernourished during much of pregnancy and throughout lactation. Both control (C) and undernourished (UN) offspring had free access to food from weaning. Rats were tested between 15 and 27 weeks of age. During repeated exposures on the same day in a rectangular observation box, UN rats moved about more and reared on their hind legs more often than controls, but defecated less frequently. Two measures of exploratory behavior, tendency to emerge from a familiar to an unfamiliar area and responsiveness to a novel object, did not differentiate the 2 groups, nor did control and UN rats differ in the rate at which they pressed a lever to produce a light stimulus in a dark Skinner box. These and other long‐term, activity studies indicate that previously undernourished rats are more active than controls in familiar, nonstressful situations.
Effect of a hand sock on prehension in infancy
Authors: Umansky Richard 
Published: January 2005

AbstractIn 4‐12 month human infants a briefly applied hand sock frequently resulted in marked prehensile disuse of the socked arm (SA) in excess of the sock's mechanical restriction. Most infants failed to reach with the SA for midline objects on a majority of trials while continuing to use the unsocked arm (UA). The SA grasp and manipulation efforts were also reduced. The onset of disuse was rapid, as was resumption of use after sock removal. The SA disuse was attributed to the effect of excess contactual input from the SA. The character of the disuse differed with age. Whereas younger infants often appeared not to recognize the option to attempt prehension with the SA, older ones were capable at times of deliberate disuse of the arm and could reverse existing patterns of SA disuse. Older infants also displayed: (1) better awareness of the handicapping effects of the sock in the framework of an improved concept of arm structure and function, and (2) better adaptive and compensatory responses including substitute use of the UA. These data were interpreted to suggest a general transition from peripheral to central control of prehensile intention during the 2nd half of the 1st year.
Indolethylamine‐N‐methyltransferase in developing rabbit lung
Authors: Lin R‐L. , Sargeant S. , Narasimhachari N. 
Published: January 2005

AbstractThe activity of indolethylamine‐N‐methyltransferase (INMT) from the rabbit lung is relatively high in the newborn and increases rapidly after birth, attaining its maximum level at 15 days of age. Between the 15th and 19th postnatal days, INMT activity declines to the mature level and remains fairly constant thereafter. The decrease in the activity of the enzyme may be due to the presence of dialyzable endogenous inhibitor(s). The inhibition of the enzyme from lungs of rabbits of varying ages by S‐adenosylhomocysteine (SAH), N, Ndimethyltryptamine (DMT), and chlorpromazine (CPZ) is reported.
The development of heart rate responses to weak and strong shock in the preweaning rat
Authors: Chalmers Donald V. , Levine Seymour 
Published: January 2005

AbstractHeart rate (HR) responses to 2 intensities (.2 and 2.0 mA) of electric shock were studied in preweaning rats at 5, 7, 9, 11, 13, 15, 17, 19, and 21 days. Both weak and strong shock elicited at least some HR acceleration at all ages. Beginning on Day 13, a deceleratory component was added to the response to weak shock. HR acceleration was significantly greater in response to strong shock on Days 5 and 7 and then again from Days 15‐21. Strong shock also elicited a relatively long‐latency bradycardia beginning with Day 11. Results are discussed in terms of the emergence of 3 response tendencies: (1) the orienting reflex; (2) the defensive reflex; and (3) a change in the state of the organism, and their possible implications for the study of preweaning shock on subsequent behavior.
Protein malnutrition in the rat: Its effects on maternal behavior and pup development
Authors: Massaro Thomas F. , Levitsky David A. , Barnes Richard H. 
Published: January 2005

AbstractRepeated time‐lapse photographic observations were used to examine the maternal behavior and pup development of female Holtzman rats maintained on either a low‐protein (12% casein by weight) or a high‐protein (25% casein) diet throughout the period of lactation. Dams fed the low‐protein diet were observed to spend more time in the nesting area with their pups than dams fed the high‐protein diet. Locomotor activity of the dams did not differ between the 2 groups. The behavioral development of the pups suckling the dams receiving the low‐protein diet was markedly depressed as compared with the controls. Included in this latter observation were pup behaviors such as movement from the nesting area, feeding and drinking from available supplies, and rearing and climbing activity. The results indicate that feeding a low‐protein diet to a lactating dam results in behavioral changes in both the dam and pups that tend to minimize the exposure of the pups to the immediate environment.
Arousal and temporal factors in imprinting in mallards
Authors: Martin James T. , Schutz Friedrich 
Published: January 2005

AbstractA number of factors affecting the learning processes in laboratory imprinting were examined. Two factors alone explain the degree to which young ducklings learn the characteristics of a given model: the length of exposure to the model, and the endogenous arousal state of the duckling. A third, the effect of muscular exertion is not warranted.The characteristics of some models are more rapidly learned than others, and the significance of this fact for biochemical studies of learning is discussed. In this study ease of learning coincided with innate preference; this suggests the presence of a neural filtering mechanism in the duckling which alters the assimilation of information into the CNS and hence controls both innate preference and learnability.
Preliminary evidence for the effects of environmental complexity on hybridization of rat brain RNA to rat unique DNA
Authors: Uphouse Lynda L. , Bonner James 
Published: January 2005

AbstractHybridization to unique DNA by RNA from brain or liver of rats given varying degrees of experience was investigated. RNA from brain of environmentally enriched rats hybridized to more unique DNA than did brain RNA from nonenriched controls. No significant differences were observed with liver RNA. This provides preliminary evidence for an increased transcription of the unique sequences of DNA in the enriched animals. The technique used has great promise for the investigation of experientially‐induced alterations in gene expression.