Human pheromones. Communication through body odour.
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Adult↗
Biomedical subjects
A Weller
Publications and source records attributed to A Weller.
A CCK(A)-receptor antagonist administered to the neonate alters mother-infant interactions in the rat.
The importance of the infant's cholecystokinin (CCK) system for eliciting optimal maternal care was examined in 6-9-day-old Sprague-Dawley rats. After administration of either vehicle, CCK-8 (1 or 8 microg/kg) or devazepide (1 mg/kg; a selective CCK(A) receptor antagonist), pups were either individually isolated (Experiment 1) or individually reunited with their dam (Experiment 2) and the rats' behavior was observed. When isolated, pups that received devazepide displayed significantly more head-lifting and wall-climbing attempts than vehicle-treated controls, suggesting that endogenous CCK dampens activity. Devazepide-treated rats were found more frequently in proximity with their mothers when reunited with them, and they emitted more ultrasonic vocalizations compared to vehicle controls. Pups treated with 1 microg/kg CCK received less body licking than vehicle controls. In addition, dams hovered and crouched over devazepide-treated pups more than over pups treated with 1 microg/kg CCK. The results suggest that endogenous CCK has a calming, quieting effect in the neonatal pup and that this, in turn, results in less infant-mother attractivity and reduced levels of maternal care.
Animals↗
Prolonged and very intensive contact may not be conductive to menstrual synchrony.
Menstrual synchrony was not found for 30 cohabiting lesbian couples (mean time living together, 35 months), for whom 3 months of menstrual data were collected prospectively. A combined analysis with two previous studies of lesbian couples (Trevathan, W, Burleson, NH, Gregory, L (1993) No evidence for menstrual synchrony in lesbian couples. Psychoneuroendocrinology 18, 425-431; Weller, A, Weller, L (1992) Menstrual synchrony in female couples. Psychoneuroendocrinology 17, 171-177) also failed to reveal synchrony. These data are considered together with a previous study of Bedouin couples which found only a moderate degree of synchrony (Weller, A, Weller, L (1997a) Menstrual synchrony under optimal conditions: Bedouin families. J Comp Psychol 111, 143-151). When women live together for an extensive period of time and have intensive social contact among them, the intensive contact may not be conducive to menstrual synchrony.
Adult↗
Inter-judge agreement in evaluation of adult attachment style: the impact of acquaintanceship.
Inter-judge agreement in the evaluation of attachment style was examined across different levels of acquaintanceship. A self-rating scale on attachment style was administered to 242 students. Then, 72 participants--25 avoidant, 25 secure, and 22 ambivalent--were invited to the laboratory in unacquainted same-sex pairs, videotaped during a five-minute conversation, and asked to rate the attachment style of their conversion partner. In addition, each participant asked four friends to rate his/her attachment style and the videotaped interactions were shown to a separate sample of strangers who rated participants' attachment styles. The results showed high correlations between participants' self-reported attachment styles and the manner in which they were perceived by their friends and conversation partners. In contrast, correlations with ratings by strangers based on videotaped interactions were low. This pattern of findings was observed in both discrete and continuous measures of attachment. The findings suggest that attachment style can be considered an observable interpresonal trait.
Adolescent↗
Assessment of menstrual regularity and irregularity using self-reports and objective criteria.
To assess subjective and objective definitions of menstrual regularity, and the relationship between them, 114 university students (mean age 20.3 years) prospectively recorded eight consecutive menstrual dates and reported whether they considered themselves 'regular' or 'irregular'. The percentage of women who reported being menstrually 'regular' or menstrually 'irregular' was compared with a classification developed according to a criterion based upon the results of their prospective menstrual records. According to self-reports and objective measures of regularity, a similar portion of the women (about 70%) were regular. But when cross-classifying regularity and non-regularity by the two procedures, it was found that only 44% of those who defined themselves as irregular were likewise defined by the objective criteria, whereas 82% of the women who defined themselves as regular were also deemed so by the objective criteria. It is concluded that some women will, and others will not, construe 'variability' as 'irregularity'.
Adult↗
The influence of natural preference for tactile stimuli on appetitive learning in rat pups.
Stimuli of the same modality tend to be organized along a "natural preference scale." This study examined the ability of six- and nine-day-old rat pups to acquire appetitive learning, when the CS was one of two differently "naturally preferred" tactile stimuli (floor textures: rug and plywood). In Experiment 1, all pups showed a relative natural preference for the rug texture over the plywood texture. Pups conditioned on the plywood texture (exposed to a sibling pup as the US) showed a robust increase in preference for the conditioned texture whereas pups conditioned on the rug texture showed a different and more moderate pattern of acquisition. Developmental differences were found only in extinction of the conditioned response: six-day-old (but not nine-day-old) pups displayed extinction of the response over four trials. Experiment 2 indicated that preexposure to the rug CS prior to conditioning (latent inhibition) did not interfere with the learning process on the rug texture. Two major alternative explanations for the differential learning patterns are discussed: motivational and catecholaminergic influences on learning. The results suggest that natural preferences may modulate early learning and memory processes.
Age Factors↗
Social play with an unfamiliar group in weanling rats (Rattus norvegicus).
Early signs of aggressive behavior toward an intruder were examined in Sprague-Dawley rats. The interactions between groups of four 24-day-old pups (2 males, 2 females) and an unfamiliar male pup from another litter were observed. Some patterns of social play were asymmetric. Compared to the playmate from the group, the unfamiliar pup was most likely to be underneath the other rats, either during play fighting or by crawling under a playmate. The single pup was most frequently involved in the following behaviors: on top (One animal climbs on top of another animal placing its forepaws on the second animal.), grooming, or crawling under a playmate. The effects of relative birth weight, ambient temperature during the lactation period, relative body weight, and relative body temperature during the observation period were studied. Results show that pups born and raised in a warm environment interacted socially more than pups raised in a colder environment. Pups lighter than the mean body weight of playmates tended to use submissive behaviors more than relatively heavier pups. Relatively heavy pups tended to use play behaviors that might be considered more aggressive during the interaction. The results suggest that under appropriate conditions, early evidence for dominance, i.e., asymmetry can be revealed.
Animals↗
[Local foreign body reactions to biodegradable implants. A classification].
Biodegradable implants are increasingly used in orthopedic and trauma surgery. Many different implants consisting of different biodegradable polymers are currently available. Different factors contribute to the biocompatibility of these implants, and local foreign-body reactions remain a matter of concern. Therefore, it is mandatory to document and compare the tissue reactions caused by various biodegradable implants in experimental or clinical studies. We have developed a standardized system of classification based on our previous experimental and clinical observations. Foreign-body reactions are differentiated into osteolysis (0-0 to 0-4), extra-articular (EA-0 to EA-4) and intraarticular (IA-0 to A-4) soft-tissue reactions.
Animals↗
Characteristics of glucose and maltose preloads that inhibit feeding in 12-day-old rats.
Nonvolumetric inhibitory control of food intake during independent ingestion was studied in rats on postnatal day 12. Pups received either sham intubation or equivolumetric (5% BW) preloads of 20% (w/v) glucose, 20% maltose, 20% 2-deoxy-D-glucose (2-DG), 0.9% NaCl, 200 mg soybean trypsin-inhibitor (SBTI) or distilled water, 5 min prior to 30-min access to a milk diet spread on the floor of a beaker. To investigate if endogenous cholecystokinin mediated any of the inhibitory effects of the preloads on intake, pups were injected IP with 1 mg/kg devazepide, a specific CCK(A) receptor antagonist, or with vehicle 30 min prior to the intake test. All preloads reduced intake (measured by percent body weight gain) compared to sham intubation. Glucose (20%) reduced intake significantly more than 0.9% saline, but not more than the preload of 20% 2-DG. This suggests that the effect of glucose can be accounted for by its preabsorptive osmotic properties because 2-DG is not actively transported or metabolized. The inhibitory effect of 20% maltose may also be due to its osmotic load, but these experiments did not provide clear evidence for this. Cholecystokinin apparently did not mediate the effect of any of the preloads except SBTI, because devazepide only reduced the inhibition produced by a preload of SBTI. These results provide further evidence that hypertonic stimuli in the stomach or small intestine provide inhibitory control of food intake by postnatal day 12.
Animals↗
Preloads of corn oil inhibit independent ingestion on postnatal day 15 in rats.
The ontogenetic development of postingestive inhibitory control of ingestion by an oil preload was examined in preweaning rats. Gastric preloads (5% b.wt) of water, mineral oil or corn oil were administered 5 min before a 30-min intake test in which pups licked milk from the floor of a test chamber. Preloads of corn oil decreased intake significantly compared with preloads of mineral oil or water on Postnatal Days 15 and 18, but not on Postnatal Day 12. Because preloads of corn oil reduced intake ore than preloads of mineral oil, it is possible that the inhibitory effect of corn oil is due to its fats rather than to its oily texture. Cholecystokinin (CCK), presumably released from the small intestine, apparently mediates part of this inhibitory effect because pretreatment with devazepide, a specific CKKA antagonist, significantly reduced the inhibition produced by corn oil.
Age Factors↗
Menstrual variability and the measurement of menstrual synchrony.
While the timing of menstrual cycles must be modifiable in order for the phenomenon of menstrual synchrony to occur, cycle variability and the occurrence of irregularly long or short cycles complicate the measurement of the process of synchronization over time and of determining whether synchrony exists for women who have lived together for a long period of time. The paper examines how each of five different ways of measuring menstrual synchrony (utilized in the literature) deals with menstrual variability and irregular cycles. On the basis of this analysis, the mathematical concept of "the limit of a sequence,' and analysis of data according to these five different approaches, we recommend the approach in which women record their onset dates after they have been together for a prolonged period of time. The observed onset differences between the women are then compared to expected onset differences, based on the assumption of random onset occurrence. A significant influence of irregular cycle lengths on synchrony was not found in this data set and in the other studies which examined this issue. Research to date has focused on a relatively narrow aspect of menstrual regularity and synchrony and has failed to emphasize the coupled pattern of events over time as well as to analyze menstrual synchrony as a cyclic system.
Bias↗
Menstrual synchrony under optimal conditions: Bedouin families.
Ovarian cycles of females living and interacting together have been shown to synchronize in a number of species. In humans, the related phenomenon of menstrual synchrony has been reported among roommates and best friends. Menstrual data were collected prospectively for 3 months from 27 Bedouin nuclear families living under conditions optimally conducive for synchrony: (a) women living together for many years, (b) a highly sexually segregated society, (c) standard living conditions, and (d) minimal use of oral contraceptives. Results show unequivocally the existence of menstrual synchrony: A 20%-25% shift toward synchrony was found for sisters-roommates, sisters-roommates who are close friends, and the family (all women in the family between 13 and 50 years of age).
Adolescent↗
Stages of acculturation as reflected by depression reduction in immigrant nursing students.
Depression amongst immigrant students from the former Soviet Union was assessed as an index of the stage of their acculturation into the new host society, Israel. At the beginning of the first year of nursing school, three groups completed the Beck Depression Inventory. The two groups of immigrants: immigrant nurses preparing for licensing (N = 26) and immigrant students (N = 16), reported mild levels of depression, while Israeli students (N = 33) were significantly less depressed, within the normal range. Six months later, both immigrant groups were within the normal range, the immigrant nurses group showing the greatest decrease in depression. This change may be explained by adaptation to the educational setting, mastering the host society's language and social anchorage. The importance of background variables for predicting depression reduction is examined. The findings are discussed within the framework of multistage models of acculturation and the implications for counseling immigrant students are presented.
Acculturation↗
Neurobehavioral development of neonatal rats after in-utero hypothyroxinemia: efficacy of prenatal thyroxine treatment.
The aim of this study was to assess the impact on neonatal neurobehavioral development of methimazole (MMI)-induced in-utero hypothyroxinemia and of correction by maternal-fetal thyroxine (T4) transfer in the rat. Two groups of pregnant Sprague-Dawley rats received MMI as drinking water from gestation day 10 until birth. From day 16 until parturition, one of these groups received daily intraperitoneal injections of L-T4 and the other received saline injections. A third (control) group drank tap water and received saline injections. From day of birth, offspring from all groups were raised by untreated foster dams. Their neurobehavioral development was monitored, on postnatal days 5-14 (N = 3/litter, from 30 litters) by experimenters blind to treatment group. Prenatal T4 treatment resulted in correction of MMI-induced delayed appearance of three different reflexes. Body-weight gain of treated pups was similar to that of controls and more rapid than development of rats treated with MMI-alone. T4 treatment did not prevent, however, MMI-induced delay in maturation of physiological landmarks (e.g. ear opening). At least a portion of the developmental delay resulting from prenatal (maternal) MMI administration may be reversed by maternal-fetal transfer of T4 administered to the gravid dam.
Administration, Oral↗
A comparison of prospective and retrospective assessments of sleep.
The main purpose of this study was to evaluate the correlations between retrospective and prospective assessments of sleep. Subjective reports of sleep characteristics and sleep quality were obtained from 146 young (20-40 years, average age 29.15) healthy men (n = 43), nonpregnant (n = 70) and pregnant women (n = 33). Three types of subjective sleep reports were obtained: (1) general estimates of sleep habits (retrospective measures); (2) sleep logs completed upon awakening on three successive workdays (prospective measures); and (3) general sleep complaints. Men showed the greatest stability in the sleep log reports, followed by nonpregnant women, with pregnant women showing the least stability. Significant positive correlations between prospective (log reported) and retrospective (general estimates) sleep measures were found only for men. However, for measures of sleep quality, such as feelings of fatigue upon awakening, women showed greater agreement between their general estimates and three nightly reports. The limitations of using retrospective estimates in sleep surveys are discussed.
Adult↗
Postingestive inhibitory controls of independent ingestion in 12-day-old rats.
The postingestive inhibitory control of independent ingestion produced by gastric preloads was investigated in 12-day-old Sprague-Dawley rats. Pups received isovolumetric (5% of body weight) preloads of saline (0.9%), glucose (5%, 10%, or 20%) or maltose (5%, 10%, or 20%) 5 min before a 30-min independent ingestion test in which pups licked milk from the floor of the test chamber. All preloads reduced intake significantly compared to the control condition in which pups were intubated, but no preload was administered. The reduction of intake produced by the isovolumetric, isotonic solutions (saline, 5% glucose, and 10% maltose) is consistent with the stimulation of a preabsorptive, inhibitory mechanism sensitive to volume. The significantly larger reduction of intake produced by isovolumetric, hypertonic solutions (20% glucose and 20% maltose) is consistent with the stimulation of an additional postingestive inhibitory mechanism sensitive to the osmotic, saccharidic, or, in the case of 20% glucose, metabolic properties of these solutions. Because preloads were given 5 min prior to the intake tests, it is likely that the site of action of both inhibitory mechanisms was preabsorptive, although a postabsorptive site for part of the inhibitory effect of 20% glucose cannot be excluded.
Animals↗
Odor-induced inhibition of intake after pairing of odor and CCK-8 in neonatal rats.
This study determined whether an odor that was paired with injections of CCK octapeptide would later come to inhibit independent feeding in neonatal rats. An odor so paired in rats that were not food or maternally deprived later reduced feeding during the infants' first independent feeding experience. Devazepide, the CCKA receptor antagonist, blocked the reduced intake when injected prior to the feeding test. These studies demonstrate that CCK is an effective unconditioned stimulus even when the animal is not eating during the conditioning process. Furthermore, the conditioned stimulus (the odor) causes behavioral change either by sensitizing a system that includes the CCKA receptor, by causing the release of endogenous CCK, or by changing some non-CCK system that enhances the processing of CCKA receptor-mediated information.
Animals↗
Ontogenetic development and pentylenetetrazol seizure thresholds in rats.
Ontogenetic differences in seizure thresholds to pentylenetetrazol (PTZ) were examined in young, developing rats (ages: 10, 18, 28, and 60 days). A subconvulsive dose of PTZ (15 mg/kg IP) was administered every 10 min and the occurrence of partial and full (clonic tonic) seizures was noted. Ten day old pups displayed complete seizures more rapidly than any of the other groups (p < .01) without any behavioral indication of going through the partial stages. Among 18 day old pups the development of early seizure stages was followed rapidly by the full seizure, while in the weaned groups the early seizure stages tended to persist much longer before the appearance of the full generalized convulsion. The preweanling rat's immature brain seems less able to suppress PTZ induced generalized convulsions compared to the brain of the older rats.
Aging↗