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Biomedical subjects

J L Millot

Publications and source records attributed to J L Millot.

15 recordsLinked to original sources
PubMed2002

Lateralization in human nasal chemoreception: differences in bilateral electrodermal responses related to olfactory and trigeminal stimuli.

The study of olfactory lateralization in humans has given rise to many publications, but the findings have often been contradictory. There is growing evidence to suggest that the nature of the olfactory stimulus influences the processes of lateralization. An important factor could be the trigeminal component. Indeed, most odorants simultaneously stimulate both olfactory (CN I) and trigeminal (CN V) systems which differ in terms of their central projections, ipsilaterally for CN I and contralaterally for CN V. The aim of this study was to investigate variations in psychophysiological measurements between a nasal input with low (phenyl ethyl alcohol (PEA)) and high (allyl isothiocyanate (AIC)) intranal trigeminal stimulation. In a first experiment (20 subjects), the intensity, hedonicity and irritation levels of stimulus were tested with a psychophysical evaluation to study the possible influences of perceptual characteristics. A second experiment (37 subjects) used bilateral electrodermal recordings and compared the skin conductance responses (SCRs) for both nasal inputs on either monorhinal and birhinal stimulations. Firstly, the electrodermal activity (EDA) results showed no differences between the two nostrils for PEA as well as AIC, but differences in relation to the type of stimulus, e.g. higher amplitude in response to AIC versus PEA. Secondly, the results indicated bilateral differences in EDA recordings related to the nature of the stimulus and are discussed in terms of hemispheric asymmetric activation.

Adult↗
PubMed2002

Recovery following peripheral destruction of olfactory neurons in young and adult mice.

Olfactory neurons (ON) which are located in the olfactory epithelium are responsible of odorous molecule detection. A unique feature of these cells is their continuous replacement throughout life due to the proliferation and differentiation of local neural precursors, the basal cells. Thus, experimental destruction of all ON induces a stimulation of basal cell division followed by tissue regeneration. The fact that ON precursors display such proliferative and neurogenic activity in adults makes these cells particularly attractive as a potential tool for nervous system repair. However, basal cell proliferation and, thus, ON production, decrease in relation to age; mostly during the first months of life. Therefore, we aimed to seek whether the ability of ON precursors to yield new functional ON in regenerative conditions was consequently impaired in adult. ZnSO4 intranasal perfusion administered to young (1 month) and adult (6 months) mice leads in a few days to total ON destruction and to hyposmia. Tissue and function restoration occurred in the following weeks in both mice groups and was preceded by a transient peak of cell division. In adults, although neurogenesis in the impaired olfactory epithelium was less efficient than in young mice, neural precursors retain their ability to provide new functional ON as indicated by the butanol detection recovery. This was achieved more rapidly than total ON regeneration, suggesting that a reduced number of reconnected ON may be sufficient for odor discrimination.

Aging↗
PubMed2001

Complexity of olfactory lateralization processes revealed by functional imaging: a review.

Currently available techniques used in neurosciences and particularly cerebral imaging are contributing to a better understanding of human perception and the treatment of sensorial information. In this field, the chemical senses (taste and smell) have received little attention when compared with the auditory, visual and tactile senses. Nevertheless, recent research has been trying to overcome this. Brain regions involved in the processing of olfactory information have been investigated in several studies including a large number dealing with the question of lateralization. However, functional asymmetry in olfaction has still not been resolved and the resulting data have not been homogeneous. In this field, the contribution of cerebral imaging studies is very important insofar as it shows that the processes of functional lateralization in olfaction depend on many factors (nature of stimulus, nature of task, characteristics of subjects ...) that future research will have to consider.

Animals↗
PubMed2001

Sex differences in human olfaction: between evidence and enigma.

The sex of individuals plays an important part in determining their olfactory abilities, with females generally being superior to males. The present review examines the way in which sex differences influence sensitivity, identification, familiarity, and recognition of odours. It also examines whether sex differences are more pronounced with some odours than others, and how sex differences are affected by the manner of testing. Two different explanations for the superiority of females over males in olfaction are evaluated.

Female↗
PubMed2001

Intercorrelations among tests of lateralisation in the BALB/c mouse.

In order to examine the reliability of lateralised behaviours, BALB/c mice were tested in three different situations: the Collins paw preference test (PPT), the rotatory swimming test (RST), and the T maze test (TMT). The results showed a significant correlation between the scores of lateralisation in the PPT and the RST, but a lack of lateralisation in the TMT. Considering the tasks involved in these tests, these results appear to support the hypothesis of close links between lateralised behaviours, emotional processes, and neural pathways.

Journal Article↗
PubMed2000

Comparison between monorhinal and birhinal olfactory stimulations in bilateral electrodermal recordings.

The study of olfactory lateralization in human subjects has given rise to many publications, but the findings have often been contradictory. Most research used either birhinal or monorhinal stimulations, but rarely a comparison between these two types of olfactory input. The aim of this study was to investigate variations in psychophysiological measurements and test each side of the nose and binasal performances. This work used bilateral electrodermal recordings and compared the skin conductance responses (SCRs) for a pleasant odorant (isoamyl acetate) and an unpleasant odorant (triethylamine) in a suprathreshold concentration on 30 dextral subjects (16 females and 14 males). First, the results reported no differences between the two nostrils but differences in electrodermal activity (EDA) in relation to the odorant: 1) higher amplitude in response to unpleasant versus pleasant odorant; 2) no differences between monorhinal and birhinal stimulations for the unpleasant odour but higher amplitude in response to birhinal versus monorhinal for the pleasant odour. Second, the results showed constant bilateral differences in EDA recordings and are discussed in terms of hemispheric asymmetry activation.

Adult↗
PubMed2000

Behavioral lateralization during spontaneous smelling tasks.

The smelling behavior of 52 right-handed subjects was videotaped during tasks involving identification and recognition of different odors. Analysis showed that men more often used the right nostril than the left whatever the odor. There was no significant difference for the women. These results support a more marked cerebral asymmetry in men than in women and a main involvement of the right cerebral hemisphere in the olfactory processes at least by right-handed men.

Adult↗
PubMed1999

Olfaction and hemispheric asymmetry: unilateral stimulation and bilateral electrodermal recordings.

The study of hemispheric asymmetry in olfaction in human subjects has given rise to many publications, but the findings have often been contradictory. This study used bilateral electrodermal activity recordings with unilateral stimulation as a measure of functional hemispheric asymmetry. A specific odorant (lavender) was used by monorhinic (single nostril) stimulation on 30 dextral subjects (20 females and 10 males). Intraindividually, the results showed no difference between the two nostrils, but all subjects exhibited a constant direction of electrodermal asymmetry: 20 subjects systematically showed a greater response amplitude for the right hand and 10 subjects systematically showed a greater response amplitude for the left hand, whatever hemisphere stimulated.

Acoustic Stimulation↗
PubMed1993

[Experimental study of olfactory and visual modalities in the communication system between child and pet dog].

Different experimental methods are set up to specify the importance of the olfactory cues in the interaction systems between the young child and his pet dog. A realistic child dummy, with an affiliative or an agonistic posture, is wearing clothes of a child who is known or unknown from the animals. The study is dealt in kennels (N(o) of dogs observed: 68) and allows to define and quantify the behaviours of the dogs in response to different combinations of visual and olfactory informations. These behaviours allow to discuss the socio-cognitive abilities of the dogs and their relational strategies determined by the integration of several functional cues.

Animal Communication↗
PubMed1990

[Child aggression by dogs: a preliminary study of risk factors].

Dog bites in children, although a genuine problem, have as yet been little studied in France from the viewpoint of epidemiology. A detailed study of 184 bites leading to management in a rabies control centre provided preliminary data on individual characteristics and behaviors of the dogs and children, as well as on features of the environment (place and time) that seem to be specifically associated with dog attacks on children. Increased insight into these risk factors should prove useful for the preventive information of children, parents, and dog owners.

Adolescent↗
PubMed1988

Maternal tactile behaviour correlated with mother and newborn infant characteristics.

Filmed observations of spontaneous interactions between mothers and their newborn infants (N = 50) were used to quantify the occurrences, duration and frequency of maternal tactile behaviours (stroking, kissing, touching the clothes, etc.). The analysis of the data shows that these maternal behaviours vary from one mother to another according to the activities of the newborn infant (sleeping, arousal but not feeding, feeding) and to different biological (sex of the infant, birthweight) and social (socio-economic status of the mother) variables. These results would suggest discussion topics concerning the differences between the mother-infant interaction systems.

Adult↗
PubMed1986

[Body contact between mother and her newborn infant. Possible effect of a prenatal variable].

We have found by looking at films of the spontaneous interactions between 50 mothers and their newborn babies that mothers behave in regard to touching their infants with negative correlation between the number of days that separate the estimated date of delivery from the actual date of delivery. All the same, if one takes into account the activity of the newborn (feeding, being awake without feeding and being asleep) it is only when the newborn is asleep that this correlation is to be avoided. There are different psychological and bio-psychological factors that can explain this phenomenon.

Adult↗