Prenatal and early sucking influences on dietary preference in newborn, weaning, and young adult cats.

Early experiences are of potential importance in shaping long-term behavior. This study examined the relative influence of prenatal and/or early postnatal experience of chemosensory stimuli on subsequent olfactory and dietary preferences of cats as newborns, at 9-10 weeks, and at 6 months. Cats were exposed to vanillin or 4-ethylguaiacol via their mother's diet either prenatally, postnatally, perinatally (prenatal and postnatal), or experienced no exposure to the stimuli (control). Newborns were given a two-choice olfactory test between the familiar "odor" and no odor; 9-10 week olds were tested for their preference between two food treats, one flavored with the familiar stimulus and the other unflavored; at 6 months, cats were given a choice of two bowls of food, one flavored with the familiar stimulus and the other unflavored. At all ages, cats preferred the familiar, and avoided the unfamiliar, stimulus. Perinatal exposure exerted the strongest influence on preference. Prenatal exposure influenced preference at all ages and postnatal exposure exerted a stronger effect as the cat aged. We conclude that long-term chemosensory and dietary preferences of cats are influenced by prenatal and early (nursing) postnatal experience, supporting a natural and biologically relevant mechanism for the safe transmission of diet from mother to young.

The psychosocial impact of orthognathic surgery: a systematic review.

The aim of this study was to review the reported psychosocial benefits of orthognathic surgery. A systematic review of the literature was conducted using MEDLINE (1966 to December 2000), Web of Science (1981 to December 2000), and reference sections of identified articles. We also hand searched key orthodontic, oral surgery, and psychology journals. No language limitations were imposed. Randomized controlled trials, other controlled clinical trials, prospective studies (with or without controls), and retrospective studies (with or without controls) were considered for inclusion. Two reviewers extracted the data and independently assessed the quality of the studies. In all, 29 studies, including a number of prospective and retrospective studies, were identified as relevant. The results of the review indicated that orthognathic patients experience psychosocial benefits as a result of orthognathic surgery, including improved self-confidence, body and facial image, and social adjustment. However, there were wide variations in the study designs and a lack of uniformity in measuring the psychosocial constructs. This made it difficult to quantify the extent and the duration of the psychosocial benefits.

Habituation in fetuses of diabetic mothers.

Fetuses of diabetic mothers exhibit maturational delays in their behaviour and disturbances in behavioural and intellectual functioning in childhood. This suggests an effect of maternal diabetes on the central nervous system of the fetus. The habituation technique enables the functioning of the higher central nervous system to be examined. A normal habituation pattern reflects an intact central nervous system. Previous studies have found abnormalities in the fetal central nervous system are reflected in habituation performance. This paper examined the habituation ability of fetuses of diabetic mothers and of non-diabetic mothers. The fetuses were tested at 28, 32 and 36 weeks of gestation. After 2 min of fetal inactivity a series of vibroacoustic stimuli were presented to the fetus. This continued until no response was observed on five consecutive stimulus presentations. The number of stimulus presentations to habituate at each gestational age was recorded. The results reveal that there was a highly significant main effect of group (F(1,47)=19.65, P<0.001). Fetuses of diabetic pregnancies took longer to habituate. There was a significant effect of gestational age (F(2,94)=44.67, P<0.0001). In both groups the number of trials to habituate decreased with advancing gestation. There was no relationship between random blood glucose levels and habituation performance. The results demonstrate that maternal diabetes affects higher aspects of central nervous system functioning in the fetus.

The discrimination of dog odours by humans.

The domestic dog is able to identify both individual conspecifics, i.e. other dogs, and individual interspecifics, e.g. humans, by smell. Whilst humans can recognise individual members of their own species using olfactory information, it is unknown whether they can identify members of any other species in this manner. We examined the ability of humans to identify individual dogs by smell. Twenty-six dog owners were required to smell two blankets, one impregnated with the odour of their own dog, the other impregnated with the odour of an unfamiliar dog. Participants were required to indicate which of the odours smelt the strongest, which smelt the most pleasant, and which of the odours belonged to their own dog. Most of the participants (88.5%) were able to recognise the odour of their own dog. They showed no significant bias, however, in responding which of the odours they thought smelt the strongest or most pleasant. The results indicate that dogs produce odours that are individually distinctive to their owners, and highlight the fact that humans can recognise members of another species using olfactory cues--an ability presumably acquired without conscious effort.

Effects of replicating primary-reflex movements on specific reading difficulties in children: a randomised, double-blind, controlled trial.

BACKGROUND: Children with specific reading difficulties have problems that extend beyond the range of underlying language-related deficits (eg, they have difficulties with balance and motor control). We investigated the role of persistent primary reflexes (which are closely linked in the earliest months of life to the balance system) in disrupting the development of reading skills. METHODS: We assessed the efficacy of an intervention programme based on replicating the movements generated by the primary-reflex system during fetal and neonatal life. A randomised, individually matched, double-blind, placebo-controlled design was used and children (aged 8-11 years) with persistent primary reflexes and a poor standard of reading were enrolled into one of three treatment groups: experimental (children were given a specific movement sequence); placebo-control (children were given non-specific movements); and control (no movements). FINDINGS: From an initial sample of 98 children, 60 children, 20 in each group were matched on age, sex, verbal intelligence quotient (IQ), reading ability, and persistent asymmetrical tonic neck reflex. For asymmetrical tonic neck-reflex levels there was a significant (group by time) interaction (p<0.001). The experimental group showed a significant decrease in the level of persistent reflex over the course of the study (mean change -1.8 [95% CI -2.4 to -1.2], p<0.001), whereas the changes in the placebo-control and control groups were not significant (-0.2 [-0.9 to 0.6] and -0.4 [-0.9 to 0.2]). INTERPRETATION: This study provides further evidence of a link between reading difficulties and control of movement in children. In particular, our study highlights how the educational functioning of children may be linked to interference from an early neurodevelopmental system (the primary-reflex system). A new approach to the treatment of children with reading difficulties is proposed involving assessment of underlying neurological functioning, and appropriate remediation.

A simple method for testing odor detection and discrimination in chicks.

A simple procedure for testing newly hatched chicks' responses to olfactory stimuli is described. Chicks that were hand held under a heatlamp became inactive and closed their eyes (as if asleep) within 2 min. Sleeping chicks displayed overt behavioral responses to an odorized q-tip (head shaking, beak clapping) that were not observed in awake chicks. Sleeping latencies were shorter for 1-day-old chicks that had been food deprived prior to testing than for chicks that had ad lib access to food and water. When airborne odors were presented by squeezing a soft plastic odor bottle near the beak, sleeping chicks' reactions to mint were of a greater magnitude than their responses to lavender or orange scents. Nonetheless, all three odors elicited more pronounced behavioral responses than did the water control stimulus. This method allows rapid testing of individual chicks for odor detection and discrimination.

Prevalence of disease in dogs purchased from an animal rescue shelter.

The prevalence of diseases suffered by dogs within two weeks of their acquisition from a rescue shelter in Northern Ireland was investigated. A postal questionnaire was completed by 556 people who had purchased a dog from the Ulster Society for the Prevention of Cruelty to Animals (USPCA) to provide information on the diseases suffered by their dog. The majority of the dogs (53.7 per cent) had an ailment the most common being coughing and diarrhoea. Of the respondents who returned their dog to the USPCA, 92 per cent did so because the animal was unhealthy. Stray dogs were more likely to have an ailment than unwanted dogs, specifically coughing, and/or skin problems. More puppies suffered from parvovirus, vomiting, and/or diarrhoea than did juveniles or adults. Adult dogs were more likely to have a cough than juveniles or puppies. There was no association between the sex of the dogs and their ailments.

Lateralised behaviour in first trimester human foetuses.

Behavioural lateralisation is a common feature of everyday behaviour, most familiar in the exhibition of handedness. Despite differing theories about the origins of laterality, little is known about their ontogenesis. This study observed the left and right arm movements of 72 foetuses at 10 weeks of gestational age, the first age at which lateralised behaviour may be observed. There was a highly significant preference for foetuses to move their right arm more than their left arm, 85% exhibiting more right arm than left arm movements. There was no difference in the amount of movements exhibited with the preferred arm, whether it be right or left. Laterality of behaviour at such an early gestational age (probably as early as it is possible for it to be observed) is unlikely to be under brain control but is probably of more muscular or spinal determination. The possibility that early differential motor behaviour may contribute to subsequent laterality of behaviour and asymmetrical brain growth, must be considered.

Chemosensory learning in the chicken embryo.

Prenatal chemosensory learning has been demonstrated in mammals, fish, amphibians, and insects, but not birds, although there is evidence of the avian's ability to learn auditory stimuli before hatching. This paper examines how exposure to a chemosensory stimulus (strawberry) prior to hatching affects subsequent chemosensory preferences of newly hatched chicks. The chicks' preferences were assessed at 2 days after hatching using an "olfactory" preference test (strawberry-smelling shavings versus water-coated shavings) and at 4 days after hatching using a "gustatory" preference test (strawberry-flavoured water versus unflavoured water). Chicken embryos were exposed to strawberry from Day 15 to Day 20 of incubation by either presenting the odour in the air around the egg, rubbing it onto the shell, or injecting it into the air space. With no exposure to strawberry before hatching, strawberry was highly aversive to chicks after hatching. However, following exposure to strawberry before hatching, chicks expressed a greater preference for (or weaker aversion to) the strawberry stimulus. Chicks exposed to strawberry before hatching drank more strawberry-flavoured water and spent more time in a strawberry-scented area than chicks having no exposure before hatching. This change in preference was specific to the stimulus experienced before hatching and was present in the absence of any posthatching exposure to the stimulus. The results demonstrate that a chick's chemosensory preferences are changed as a result of experience with a stimulus before hatching and are suggestive of learning. The results, similar to those obtained in other animal groups, indicate the universality of "prenatal" chemosensory learning in the animal kingdom. A possible role of embryonic chemosensory learning for recognition is discussed.

Developmental aspects of kin recognition.

The ability to recognise kin requires the individual to possess a variety of abilities. Individuals must produce a cue which indicates relatedness, they must process this cue to determine relatedness and then must act on this cue. Research has concentrated on the first and final stage of this process, i.e., the cues of kinship and kin correlated behaviour. Little attention has been paid to how individuals process cues to determine relatedness. This paper discusses how individuals 'recognise' kin, the exhibition of kin correlated behaviour and considers the role of the MHC in these processes. Two broad theories have emerged to explain how individuals recognise their kin: either a recognition gene(s) or some experiential mechanism. In mammals there is no evidence to suggest that recognition (the processing of the cue) is under genetic control but rather is the result of experience, learning about related individuals during development. Moreover studies on kin recognition in the domestic dog suggest that all kin are not recognised by the same process but different classes of kin, parents, siblings may well be recognised using different means. Studies of kin correlated behaviour suggest that the behaviour exhibited towards kin by Mongolian gerbils is mediated by the environment. Factors of environmental familiarity, sex and developmental age all affect the response of individuals to kin and non-kin. In these situations the ability to recognise kin does not change but the exhibition of kin correlated behaviour changes according to environmental conditions. These studies indicate that kin recognition may not be the 'unified' process previously thought and thus any explanations of the proximate and ultimate causation of kin recognition need to encompass this complexity. The question remains of whether the MHC is complex enough to do so.

Fetal memory: does it exist? What does it do?

Whether fetal memory exists has attracted interest for many thousands of years. The following review draws on recent experimental evidence to consider two questions: does the fetus have a memory? And, if so, what function(s) does it serve? Evidence from fetal learning paradigms of classical conditioning, habituation and exposure learning reveal that the fetus does have a memory. By comparison little attention has been paid to the possible function of memory. Possible functions discussed are: practice, recognition of and attachment to the mother, promotion of breastfeeding, and language acquisition. It is concluded that the fetus does possess a memory but that more attention to the functions of fetal memory will guide future studies of fetal memory abilities.

Human fetal behaviour and maternal cocaine use: a longitudinal study.

This paper reports a series of ultrasound observations on a human fetus from 21 weeks of gestational age at two weekly intervals to term. The mother, until 18 weeks of gestational age, was a user of cocaine but after this age used cocaine only once at 31 weeks gestation. The behaviour of this fetus was compared to a group of 10 similar aged fetuses who were not exposed to cocaine. Exposure to cocaine resulted in prolonged periods of inactivity interspersed with periods of increased general activity and an increased number of startles. This was particularly evident immediately following exposure to cocaine but behaviour appeared to become more normal with time as the mother stopped using cocaine. The behavioural states of the cocaine exposed fetus were different from unexposed fetuses. Longer periods were spent in States 1F and 4F and less time in State 2F. Furthermore the incidence of periods where no states were observed was considerably higher. These observations demonstrate that maternal cocaine use disrupts the behaviour of the fetus indicating a direct effect on the CNS. The value of prenatal behavioural observations to assess the effects of neurotoxic agents is demonstrated.

Development of fetal hearing.

Previous research has revealed that the human fetus responds to sound, but to date there has been little systematic investigation of the development of fetal hearing. The development of fetal behavioural responsiveness to pure tone auditory stimuli (100 Hz, 250 Hz, 500 Hz, 1000 Hz, and 3000 Hz) was examined from 19 to 35 weeks of gestational age. Stimuli were presented by a loudspeaker placed on the maternal abdomen and the fetus's response, a movement, recorded by ultrasound. The fetus responded first to the 500 Hz tone, where the first response was observed at 19 weeks of gestational age. The range of frequencies responded to expanded first downwards to lower frequencies, 100 Hz and 250 Hz, and then upwards to higher frequencies, 1000 Hz and 3000 Hz. At 27 weeks of gestational age, 96% of fetuses responded to the 250 Hz and 500 Hz tones but none responded to the 1000 Hz and 3000 Hz tones. Responsiveness to 1000 Hz and 3000 Hz tones was observed in all fetuses at 33 and 35 weeks of gestational age, respectively. For all frequencies there was a large decrease (20-30 dB) in the intensity level required to elicit a response as the fetus matured. The observed pattern of behavioural responsiveness reflects underlying maturation of the auditory system. The sensitivity of the fetus to sounds in the low frequency range may promote language acquisition and result in increased susceptibility to auditory system damage arising from exposure to intense low frequency sounds.

Frequency discrimination by the fetus.

The ability to discriminate between acoustic signals of different frequencies is fundamental to the interpretation of auditory information and the development of language perception and production. The fact that the human fetus responds to sounds of different frequencies raises the question of whether the fetus is able to discriminate between them? To investigate whether the fetus has the ability to discriminate between different pure tone acoustic stimuli and different speech sounds the following study used an habituation paradigm and examined whether the fetus could discriminate between two pure tone acoustic stimuli, 250 Hz and 500 Hz, or two speech sounds, [ba] and [bi], at 27 and 35 weeks of gestational age. The results indicated that the fetus is capable of discriminating between the different sounds, i.e. 250 Hz and 500 Hz and [ba] and [bi] at 35 weeks of gestational age but less able at 27 weeks of gestational age. The implications of this for the development of the auditory system are discussed.

Long-term retention of kinship recognition established during infancy in the domestic dog.

The ability of the domestic dog to recognise its kin, and to retain this information once acquired, was studied in this paper. Dogs were examined for their ability to recognise their siblings, offspring to recognise their mother, and mothers to recognise their offspring, using a series of two choice tests. The results revealed that, at 4-5.5 weeks of age, pups can recognise their siblings and their mother, and mothers can recognise their offspring. The preference of pups at this age appears to be strongest for their mother. Olfactory cues are sufficient for this recognition to take place. At approximately 2 years of age, and having been separated from their offspring from 8-12 weeks after their birth, mothers were able to recognise their now adult offspring and these adult offspring could recognise their mothers. Siblings could only recognise one another if they had been living with a sibling (not the test animal). Dogs living on their own were unable to recognise their siblings. Thus dogs can recognise their kin, retaining this information for a period of two years in the case of mother-offspring. It is suggested that mother-offspring and siblings are recognised by different mechanisms.

Fetal eye movements.

Since 1981, when eye movements of the human fetus were first reported, the study of fetal eye movements has increased, mainly focusing on the ontogenesis of eye movements and as one parameter of behavioral states. Using real-time ultrasound, fetal eye movements can be clearly observed from 14 weeks of gestational age. Fetal eye movements may be described in terms of their pattern, frequency and incidence of periods containing eye movements and no eye movements. Furthermore, the relationship of eye movements to other behaviors may be used to give information on the integration of central nervous system function. A picture of normal fetal eye movements can be constructed and used to detect abnormalities in eye movements which can indicate underlying abnormalities of the central nervous system. This paper concludes that, although in its early stages, the study of fetal eye movements holds promise for a greater understanding of brain development and the assessment of the condition of the fetus.