Physically aggressive boys from age 6 to 12 years. Their biopsychosocial status at puberty.
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Adolescent↗
Biomedical subjects
B Schaal
Publications and source records attributed to B Schaal.
Gas chromatographic-mass spectrometric method to characterise the transfer of dietary odorous compounds into plasma and milk.
The flavours contained in a mammalian mother's milk can exert a marked influence on her offspring's proximate suckling behaviour and later preferences. The aim of this study was to establish a reliable analytical procedure to characterise the mammary transfer of selected volatile constituents of maternal food from non-pregnant and recently parturient ewes. Six known volatile compounds, most representative of cumin aroma (alpha-pinene, gamma-terpinene, cuminaldehyde, p-cymene, limonene and cineole), were traced in the blood and milk of ewes fed with cumin seeds, using liquid-liquid extraction combined with gas chromatography-specific ion monitoring mass spectrometry. Among the six cumin odour markers, only one, p-cymene, was transferred in quantifiable amounts into the venous plasma. The other cumin markers could only be detected as traces corresponding to amounts lower that the limit of quantification. In milk, four of the cumin markers could be detected, and two of these were quantified.
Animals↗
Fetal sensory competencies.
A growing body of evidence is available about the functioning of fetal sensory systems during gestation. This article aims at reviewing data concerning (i) the presence of potential sensory stimulation in the fetal milieu, (ii) the sequential functional development of the sensory systems and (iii) physiological and behavioral responses of fetuses to various types of stimulation. Human data are compared with data collected in other mammalian species. Most studies have investigated auditory and chemosensory (olfactory and gustatory) responsiveness of the fetus in the second half of gestation. They demonstrate that (i) motor and heart rate responsiveness depends on gestational age and characteristics of stimulation; (ii) fetal sensory experience has short- and long-term effects at morphological, functional and behavioral levels (for example transnatal learning). The clinical consequences of the fetal sensory functioning are developed.
Female↗
Male testosterone linked to high social dominance but low physical aggression in early adolescence.
BACKGROUND: The association of male pubertal testosterone with social dominance and physical aggression was studied in a population sample of boys followed from age 6 to 13 years to understand the origin of the links between violent behavior and gonadal hormones. METHOD: Physical aggression was assessed from the end of kindergarten to the end of elementary school by teachers and peers (aged 6 to 12 years). Social dominance and testosterone levels were assessed at 13 years of age during a 1-day visit to a laboratory with four unfamiliar peers. RESULTS: Boys perceived as socially dominant by unfamiliar peers were found to have concurrently higher levels of testosterone than boys perceived as less socially dominant. In contrast, boys who had a history of high physical aggression, from age 6 to 12, were found to have lower testosterone levels at age 13 compared with boys with no history of high physical aggression. The former were also failing in school and were unpopular with their peers. CONCLUSIONS: Both concurrent and longitudinal analyses indicated that testosterone levels were positively associated with social success rather than with physical aggression. High testosterone levels in adolescent boys may thus be regarded as a marker of social success in a given context, rather than of social maladjustment as suggested in previous studies.
Adolescent↗
Facial responsiveness to odours in normal and pervasively developmentally disordered children.
The facial responsiveness of 10 mutic children with pervasive developmental disorder (PDD) and 10 normal (N) children matched for sex and chronological age were covertly videotaped while presented with a set of odours contrasted in hedonic valence. Hedonic ratings of the stimuli were obtained both from the group of N subjects and a panel of adults. Two methods were used to measure facial responses in the same subjects. The first method consisted in an analysis of facial movements with the Facial Action Coding System. Results show that PDD and N subjects displayed distinct action units in response to unpleasant odours. PDD subjects typically displayed muscular actions indexing negative experience, while N subjects showed more smiles. With the second method, odour-elicited facial behaviour was rated by a panel of observers, who were asked to judge whether the subjects were exposed a pleasant, neutral or unpleasant smell. The facial responses to unpleasant odours were classified more accurately in PDD than in N subjects. These findings suggest a functional ability to sense the hedonics attached to odours, but a deficit of socialization of hedonic facial displays in developmentally disordered subjects.
Adolescent↗
Longitudinal patterns of heart rate and fighting behavior in 9- through 12-year-old boys.
OBJECTIVE: To assess the temporal stability of heart rate and to examine its relationship with fighting behavior. METHOD: Heart rate at ages 9 through 12 was compared to a composite measure of fighting behavior in three cohorts of low socioeconomic status boys (n = 138; two cohorts of boys who had been rated as having disruptive behavior problems in kindergarten and one normative cohort) while controlling for body size, pubertal status, and level of family adversity. RESULTS: Heart rate showed moderate stability at 1- and 2-year intervals in two of the three cohorts. The composite fighting score was related to heart rate for 11-year-old boys in the normative cohort and 12-year-old boys in one of the disruptive cohorts. CONCLUSION: These data support the conclusion that there is a relationship between heart rate and aggression even within a low socioeconomic status sample.
Aggression↗
Responsiveness to the odour of amniotic fluid in the human neonate.
Two-day-old newborns were videotaped during a double-choice test contrasting the odours of their amniotic fluid (AF) and of a control stimulus. To control for early motor asymmetries, the lateral position of both stimuli was balanced both between and within subjects. On average, neonates oriented their nose for a significantly longer duration toward the odour of AF. Regardless of the nature of the stimulus, neonates also evinced a marked head-turning bias to the right side. The nature of the odour stimulus and side of presentation interacted so that infants turned their nose longer to the AF odour when it was presented from the right side. These data indicate that newborns can detect the AF odour, and that they remain attracted towards it for at least 2 days after birth.
Amniotic Fluid↗
Development of exclusive mother-young bonding in sheep and goats.
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Animals↗
Olfaction in utero: can the rodent model be generalized?
In this article we discuss five requirements that theoretically must be fulfilled for transnatal chemosensory learning to occur in three placental species, the rat, the sheep, and the human, viz. (1) minimum or partial maturity of nasal chemoreceptor systems, (2) efficient odorivector compounds in the fetal environment, (3) the ability to memorize chemosensory information across birth, (4) perinatal continuity in chemical signals, (5) neonatal ability to detect air-borne odorants previously experienced in the aquatic environment. A substantial body of data is reviewed for the rat, in which fetal chemosensation is now firmly established. The less studied ovine perinate also shows preliminary evidence of nasal chemoreception and of postnatal retention of prenatally experienced odorants. Concerning the human species, we discuss extensive anatomical data supporting nasochemoreception in utero, but as yet no direct or indirect functional demonstration is provided. Furthermore, the strongest evidence of odorivector compounds in amniotic fluid is from human data. The results presented allow generalization of chemosensory functioning in utero in the species considered.
Animals↗
Behavioural and cognitive characteristics of conduct disordered-hyperactive boys from age 6 to 11: a multiple informant perspective.
Three subgroups of kindergarten boys (stable conduct disordered-hyperactive (SCDH), stable conduct disordered (SCD), stable non-deviant control (SC)) were defined and followed up three, four and five years later in primary school. Using assessments from multiple informants (teachers, mothers, peers, self), the results showed that SCDH boys were more hyperactive (i.e. overactive/inattentive) and displayed a greater diversity of conduct problems in school and home at follow-up compared to the other groups. These results and the fact that during early adolescence SCDH boys tend to develop a worse prognosis than SCD boys suggest that they should be distinguished.
Antisocial Personality Disorder↗
Individual olfactory signatures as major determinants of early maternal discrimination in sheep.
Responses of recently parturient ewes to their familiar versus separated (i.e., unfamiliar) twin lambs were observed in an attempt to elucidate further the characteristics of the phenotypic traits (signatures) mediating maternal recognition and bonding. Ewes responded more positively to their familiar lamb than to its twin that had been isolated at birth. Nonetheless, those same mothers also discriminated between their separated twin and unfamiliar alien lambs. Alien lambs elicited similar rejection behavior regardless of whether they had been housed with their own mother or in isolation prior to testing. Lambs appear to have individually distinct (olfactory) signatures; however, the signatures of twin siblings may be sufficiently similar to enable the mother to detect a resemblance. No evidence suggests that acquired maternal labels play a role in either the acceptance of the ewe's own lamb(s) or rejection of aliens.
Animals↗
[Nasal chemoreception in utero: preliminary experiences in fetal sheep].
Intranasal injections of a fragrant solution of 2-methyl-2-thiazoline elicited significant heart rate decelerations in late pregnancy fetal sheep, while the injection of a control fluid (isotonic saline) had no effect. This result indicates that the ovine fetuses are able to detect nasally administered odorants, as previously demonstrated in the fetuses of murine rodents.
Administration, Intranasal↗
[Olfactory stimulation in the relationship between child and mother].
In this paper, we report new data on mutual olfactory recognition between mother and child. Newborn infants were filmed since birth. When awakening in the mother's room at the Clinical Hospital, they were confronted with a cotton pad impregnated with diverse secretions of the mother and a cotton pad impregnated with the same secretions of another mother or a pad with no specific odour. We used a double-blind technique. By analyzing the films, frame by frame, we found that the whole area swept by the nose and the arms was significantly decreased in the child whose nose came into contact with the "mother" pad. The method could be used to study other sensory abilities in the baby. The olfactory abilities of the mother in relation to the baby were also tested with the double-blind principle. We found (i) on the 3rd and 4th days after birth, most mothers recognized the baby's odour, (ii) this faculty decreased from the 4th to the 6th day, and finally (iii) increased from the 8th day. These results are discussed. We also found that one-third of 3 to 5 years old children more often chose a tee-shirt worn against the mother's skin for 2 to 3 days than any other tee-shirt (worn by an alien mother or with no specific odour). It appears that olfactory cues can play a role in the attachment of the baby to its mother, and that they still are involved in that process when the child is between 3 and 5 years old.
Adult↗
Psychobiological consequences of two different weaning methods in sheep.
Weaning is associated with a break in the mother-infant contact. In sheep, under natural conditions, the rupture of the social bond is progressive. In contrast, weaning imposed by breeders may result in psychobiological disturbances. The aim of this experiment was to measure the behavioural, hormonal and immune consequences of two types of sudden weaning: total separation (TS) and partial separation (PS), in 42 Ile-de-France ewes and their 60 lambs. TS animals (lambs and ewes) vocalized less frequently and for a shorter period of time than did the PS animals. Neither the plasmatic cortisol level in lambs nor the humoral response of dams and young were modified by the two weaning methods. In contrast, the excretion of coccidial oocysts increased significantly after weaning in TS lambs only and the growth rate of TS females was lower than that of the other lambs. These results suggest that these methods of rupture of mother-young social contact have only limited negative consequences on both partners in sheep, contrary to primates and rodents.
Animals↗
Immediate postnatal sucking in the rabbit: its influence on pup survival and growth.
This study was aimed at characterising the impact of immediate postnatal sucking on pup survival and development. The interactive effects of postnatal success with the day 0 weight of pups, the nest-access regimen (controlled or free) or parity of females was investigated. Pups (n = 900) were categorised according to their initial ingestion of colostrum. In primiparous does: (1) pup mortality between d0-d10 was higher for unsuccessful than for successful early suckers; (2) lighter d0-weight reduced survival for unsuccessful but not for successful pups; (3) free nest-access of females annihilated the survival advantage fostered by the initial sucking success. In secondiparous does, these impacts waned. Finally, whatever the does' parity, only d0-weight influenced pup weight-gain between d0-21. Thus, pup survival seemed to depend (at least in primiparae) on their ability to suck right after birth, and to display a pattern of energy saving without being disturbed by the females' nest entries.
Animals↗
Behavioural, growth and immune consequences of early weaning in one-week-old large-white piglets.
Genetic improvement in sows' prolificity is limited by their milk capacities, which do not allow all piglets to survive or grow normally. This experiment compared the behaviour, growth and immune responses of piglets that were weaned early at 6 days of age (EW) vs. control Large White piglets' (C) suckled by their mothers. Behaviour of 9 litters of 5 to 8 piglets in each group were observed from d5 to d20. All piglets were weighed from birth to d74. Three piglets from each group were slaughtered on d36 for immunological analysis. Until they began to eat dry food, EW piglets walked and vocalised more than C piglets. After that time, when resting, they were less often lying down and more frequently in contact with littermates under the heater. Aggressive behaviour and belly-nosing were more frequent. They displayed a more marked growth check after weaning than did C piglets until 28 days of age. In EW piglets, at 36 days of age, there was a higher density of T- and B-lymphocytes in the gut epithelium and lamina propria, fespectively, in relation to the size of lymphoid follicles of Peyer's patches. The results indicate great behavioural adaptation capacities of very early-weaned piglets, together with earlier maturation of their gut immune system.
Adaptation, Physiological↗