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Biomedical subjects

C J Wysocki

Publications and source records attributed to C J Wysocki.

At least 37 records · Page 2Linked to original sources
PubMed1992

Hand preference and age in the United States.

A survey of 1,177,507 U.S. men and women between the ages of 10 and 86 included questions regarding hand preference for writing and throwing. Three effects were observed. Individuals with at least some left motoric bias comprised a smaller percent of the population with advancing age. This finding provides large-scale confirmation of a previously described phenomenon. Among sinistrals, concordance for writing and throwing was 2.2 times as prevalent as left-writing with right-throwing, and 4.1 times as prevalent as right-writing with left-throwing. These sinistral subpopulations displayed distinct and stable prevalence prior to age 50 and changing patterns of prevalence subsequent to age 50. The results confirm a decrease with age in the prevalence of sinistrality, but indicate that age-specific rates of mixed- and left-handedness are distinct. The implications for hypotheses regarding age-related change in the prevalence of sinistrality are discussed.

Adolescent↗
PubMed1991

Consequences of removing the vomeronasal organ.

In the last decade, research in our laboratories has focused on the effects of deafferentation of the mammalian chemosensory vomeronasal organ (VNX). Many different assays have been conducted and the results of some are briefly reviewed in this contribution, including the effects of VNX on neuroanatomical assessments using histochemistry (lectin binding) and immunohistochemistry (LHRH), male mouse and prairie vole ultrasonic vocalizations and hormone surges in response to cues from females, male mouse courtship and sexual behavior, territorial marking and inter-male aggression, the production of a puberty-altering substance found in mice, activation of reproduction in female voles (who generally do not exhibit estrous cycles) and maternal behaviors by female mice, including aggression directed toward intruder males. In some instances, the otherwise detrimental effects of VNX can be overcome by experience prior to deafferentation, especially in assays that are dependent upon expressions of behavior. In other situations, experience may have little impact on amelioration of the effects of VNX. The essential conclusions of this work focus our attention on reproductive physiology and behavior and a role for the vomeronasal organ in the perception of pheromones that modulate these functions.

Animals↗
PubMed1991

Activation of reproduction in nulliparous and primiparous voles is blocked by vomeronasal organ removal.

Chemical cues from male voles activate reproduction in female prairie voles (Microtus ochrogaster). Twelve hours of contact with a male, followed by exposure to his soiled bedding for 2 days, is sufficient to initiate follicular maturation and induce uterine hypertrophy. Our recent work indicates that the chemosensory vomeronasal organ (VNO) can mediate this response. Here, we examined whether other sensory systems can acquire the ability to activate female reproduction as a result of learning or experience. To explore this issue, the VNO was removed (VNX) from nulliparous and primiparous females who were then exposed to cues from males. In Experiment 1, we found that nulliparous VNX females had lower uterine and ovarian weights than did sham-operated females. In Experiment 2, we determined that sexual experience did not ameliorate the reproductive deficits normally induced by VNX. The present results contrast with those of previous studies suggesting that males of some rodent species, when allowed reproductive experience prior to VNX, can utilize other sensory systems to mediate subsequent reproductive responses. We conclude that the role of the VNO in transducing chemosensory information is crucial for coordinating the reproductive efforts of male and female prairie voles.

Animals↗
PubMed1989

Changes in sensitivity to the odor of androstenone during adolescence.

While it has been reported that most, if not all, very young children are able to detect the odor of 5 alpha-androst-16-en-3-one (androstenone), approximately 40-50% of human adults cannot detect its odor. The present study focused on changes in sensitivity to androstenone during adolescence, which may account for this discrepancy. Sensitivity to androstenone was determined in 247 subjects aged 6 to 50. There was a significant increase in the number of males anosmic to androstenone between 9-14 and 15-20 years of age, and a significant increase in threshold with age among males able to detect the odor. We infer that a smaller percentage of females than males becomes anosmic to the odor of androstenone during development, and those able to detect it apparently show a decrease in threshold with age. No age-related changes were observed in tests of pyridine or d,l-beta-phenylethylmethylethylcarbinol (PEMEC).

Adolescent↗
PubMed1989

Vomeronasal organ and social factors affect urine marking by male mice.

Adult CF-1 male mice cohabited for 15 days with three different females (EXPERIENCED) or remained physically isolated (INEXPERIENCED) prior to removal of their vomeronasal organs (VNX) or a SHAM procedure. Subjects were tested one month after surgery for urine marking in response to a stimulus male, a stimulus female, or no stimulus animal on the opposite side of a screened partition. VNX males exhibited a significant reduction in urine marking compared to SHAM males. EXPERIENCED VNX males deposited urine in amounts that were intermediate to SHAMs and INEXPERIENCED VNX males. These results suggest that deficits in urine marking behavior that result from loss of vomeronasal chemoreception may be ameliorated by prior sexual and/or social experience with females.

Animals↗
PubMed1989

Vomeronasal organ removal and female mouse aggression: the role of experience.

Removal of the vomeronasal organ (VNX) from female mice had little effect upon fecundity, nest building and pup retrieval. Surprisingly, VNX significantly affected aggression by lactating females. Normally, lactating females will attack and fight intruders placed into the home cage, especially if the intruder is an unfamiliar male. In Experiment 1, we determined that VNX prior to sexual experience totally eliminated this type of aggression. Intact females were highly aggressive, but much more so to unfamiliar than to familiar males. Copulation prior to surgery did not ameliorate the effects of VNX; again, none of the VNX females were aggressive (Experiment 2). In Experiment 3, attacks and fights by previously aggressive primiparous females also were eliminated or significantly suppressed following VNX. Even when the testing occurred later during the postpartum period and for extended periods of time, this same suppression of aggression held following VNX. We conclude that aggression by lactating female mice is under strict mediation by chemosignals detected by the vomeronasal organ.

Aggression↗
PubMed1989

Ability to perceive androstenone can be acquired by ostensibly anosmic people.

Nearly half the adult human population does not perceive an odor when sniffing androstenone (5 alpha-androst-16-en-3-one), a volatile steroid found in human perspiration, boar saliva, some pork products (e.g., bacon), truffles, and celery. This variation in ability to perceive androstenone has a significant heritable component, suggesting that androstenone insensitivity is in part determined genetically. We now report that the ability to perceive androstenone was induced in 10 of 20 initially insensitive subjects who were systematically exposed to androstenone. Since olfactory neurons of the olfactory epithelium undergo periodic replacement from differentiating basal cells, and assuming the induction of sensitivity to be peripheral, we propose that a portion of the apparently anosmic human population does in fact possess olfactory neurons with specific receptors for androstenone. Such neurons may undergo clonal expansion, or selection of lineages with more receptors or receptors of higher affinity, in response to androstenone stimulation, much in the manner of lymphocytes responding to antigenic stimulation, thus raising odor stimulation to the level of conscious perception. As a guide to further study of the genetics and mechanism of variation of androstenone perception, we provisionally envisage three categories of human subjects, the truly anosmic, the inducible, and those subjects who either are constitutionally sensitive or have already experienced incidental induction.

Androstenes↗
PubMed1988

Ultrasonic vocalizations by adult prairie voles, Microtus ochrogaster.

Male and female Microtus ochrogaster were presented with anesthetized and awake conspecifics while ultrasonic vocalizations (USVs) were monitored. Males produced significantly more USVs than females during 5-min testing sessions. Males tended to produce more USVs to unfamiliar females than to familiar female siblings. Sexual experience led to increased USV scores by males. These results suggest that USVs by male prairie voles communicate to females the male's gender and his availability for reproductive behavior.

Animals↗
PubMed1987

Removal of the vomeronasal organ disrupts the activation of reproduction in female voles.

The reproductive system of female prairie voles remains quiescent in the absence of stimulation from males; however, chemosignals from males are capable of at least partially activating female reproduction. In other species, the vomeronasal system mediates some of the reproductive responses of females to males. We found that surgical removal of the vomeronasal organ (VNX) from adult female prairie voles impeded reproductive activation in response to pairing with stud males: ovarian and uterine weights of VNX females paired with stud males for 24 or 60 hours were significantly less than those of normal (NORMAL) or sham-operated (SHAM) females. Furthermore, 8 of 9 NORMAL, 10 of 13 SHAM, but only 4 of 9 VNX females paired with stud males for 60 hours mated. VNX females, however, were still able to use chemosensory cues to locate food. Behavioral observations of females encountering stud males were similar for VNX, SHAM and NORMAL females. We conclude that vomeronasal chemoreception may be a primary component of reproductive activation in female prairie voles, presumably by mediating neuroendocrine responses to chemosignals.

Animals↗
PubMed1987

Behavioral responses of male guinea pigs to conspecific chemical signals following neonatal vomeronasal organ removal.

Following vomeronasal organ removal or sham surgery at 4-7 days of age, male guinea pigs were tested for responsiveness to conspecific chemical uses as infants and again as adults. In the first experiment, vocalizations in response to soiled home cage bedding and male bedding were monitored twice prior to surgery and twice weekly for four weeks. Home cage cues elicited more vocalizations than did male bedding in both groups; however, there was no effect of vomeronasal organ removal. When tested as adults in a second experiment, animals without vomeronasal organs exhibited depressed investigative responsiveness and vocalizations to female genital smears. The data from the first experiment fail to indicate a role for the vomeronasal organ in infantile response to conspecific odor. However, the second experiment demonstrates that adult responses to similar odors are substantially depressed by an absence of the vomeronasal organ.

Aging↗
PubMed1986

Distribution of beta 2-microglobulin in olfactory epithelium: a proliferating neuroepithelium not protected by a blood-tissue barrier.

The olfactory neuroepithelium is unique in adult vertebrates in that bipolar sensory neurons are constantly dying and being replaced. The sensory neurons are also unusual because they are directly exposed to the external environment via their dendritic processes in the nasal cavity. Surveillance of this tissue by major histocompatibility complex (MHC) class I-restricted cytotoxic T cells would presumably serve as an important means of defense against foreign pathogens. Although adult brain shows a lack of class I molecules, it has not been reported if either proliferating neurons or sensory neurons in olfactory neuroepithelium also lack class I. To examine olfactory neuroepithelium, an antiserum against beta 2-microglobulin (beta 2-m), the invariant light chain associated with all class I molecules, was employed as a general probe in an immunocytochemical assay. beta 2-m was detected in columnar respiratory epithelium, blood vessel walls, and a small population of interstitial cells in the lamina propria, but no cell in the olfactory neuroepithelium stained for beta 2-m. Parallel patterns were obtained in the vomeronasal organ. These results suggest that lack of beta 2-m, and presumably class I, may be a general phenotype of neuronal cells regardless of their mitotic state or exposure to environmental antigens.

Animals↗
PubMed1986

Mediation of male mouse urine marking and aggression by the vomeronasal organ.

The effects of vomeronasal organ removal (VNX) on male mouse urine marking and aggressive behaviors were investigated. In three different stimulus conditions VNX male marking rates were about half that of sham-operated males. Aggressive behavior was tested by pairing males with male-urine-swabbed castrate males. Only 1 of the 12 VNX males displayed normal levels of fighting behavior and 6 did not initiate any fights during the aggression tests. These results indicate that normal male aggressive and urine marking behaviors are dependent on the presence of an intact vomeronasal system for their expression.

Aggression↗
PubMed1986

70-kHz vocalizations by male mice do not inhibit aggression in lactating mice.

Two experiments investigated the relationship between adult male 70-kHz vocalizations and aggression by lactating female mice (Mus domesticus). Intact, vocalizing males, surgically devocalized males, and naturally nonvocalizing males were used to assess the effects of high frequency vocalizations on maternal aggression. The emission of high frequency vocalizations promoted aggressive behavior by the females. In both experiments, lactating females attacked the vocalizing males more rapidly and showed a higher incidence of aggressive behaviors toward these males than they did to the nonvocalizing male. We suggest that these vocalizations are only one of many situational cues that the female uses to determine her final behavioral response.

Aggression↗
PubMed1985

Mouse vomeronasal organ: effects on chemosignal production and maternal behavior.

Adult male mice excrete a urinary chemosignal that accelerates puberty in females, whereas group-housed female mice excrete a urinary chemosignal that delays puberty in young females. We found that: (1) the excretion of the puberty-acceleration chemosignal by males persisted in the absence of the vomeronasal organs and (2) the puberty-delay chemosignal was not present in the urine of group-housed females whose vomeronasal organs had been surgically removed (VNX), but was present in the urine of group-housed females subjected to sham surgery (SHAM). These results suggest that in males, vomeronasal chemoreception does not affect the excretion of the puberty-acceleration chemosignal, but that in females, the vomeronasal organ receives chemosignals that influence the excretion of the puberty-delay chemosignal. Additionally, we found no difference between SHAM and VNX females in rates of conception, litter size, pup growth, pup recognition, or maternal behavior, indicating that normal maternal processes are expressed in the absence of an intact accessory olfactory system.

Animal Communication↗
PubMed1985

Extinction of response to urine odor as a consequence of vomeronasal organ removal in male guinea pigs.

It has been found that removal of the vomeronasal chemoreceptor organ (VNO) in male guinea pigs disrupted investigatory responses to conspecific odors but this disruption was time-dependent; immediately following surgery, behavior appeared almost normal, whereas several months following surgery, animals became very unresponsive to conspecific odor. It was hypothesized that in the absence of a functional VNO, the main olfactory system (MOS) was capable of maintaining response to conspecific odor but that this response extinguished following repeated exposures. However, postsurgical change in the central nervous system, unrelated to exposure to the bioassay, remained a possible explanation. In order to separate these hypotheses, the VNO was surgically removed in two groups of animals (A and B), and a third group (C) experienced sham surgery. Beginning 3 weeks following surgery, males in Groups A and C were given two standard urine-response tests/week for 24 weeks. Initiation of testing of Group B animals was delayed until Week 15 following surgery. Results indicated that (a) responses of Group A declined relative to those of Group C, (b) at the first postsurgical test, Group B was as responsive to urine as Group C and much more responsive than Group A and (c) a decline in responses for Group B occurred during tests after Week 15. The data therefore strongly supported the extinction hypothesis. The MOS is capable of eliciting a high level of investigatory behavior in response to female urine odors, but in the absence of the VNO, this response wanes, perhaps due to a loss of reinforcing properties associated with VNO stimulation.

Animals↗
PubMed1985

Chemosensory recognition of mouse major histocompatibility types by another species.

Mice can recognize one another by individually characteristic body scents that reflect their genetic constitution at the extremely polymorphic major histocompatibility complex (MHC) of genes on chromosome 17. Reproductive behavioral manifestations of this sensory communication system include MHC-related mating preferences and neuroendocrine responses that affect preimplantation pregnancy and arise from the MHC-related scent of alien males. We have shown previously that mice can be trained in a Y maze to distinguish the scents of urine of congeneic mice that differ genetically only at the MHC. By means of an automated olfactometer, we now show that rats also can similarly distinguish the urinary scents of MHC congeneic mice. Thus, the mode of individual recognition that depends on scents determined by MHC genes can operate across species barriers.

Animals↗
PubMed1985

Chemosensory and neural influences on photoperiodic responsiveness of laboratory rats.

Olfactory bulbectomy unmasks photoperiodic responsiveness in normally nonphotoperiodic rats. We assessed whether the photoperiodic effects of bulbectomy reflect disruption of chemosensory input. At 26-28 days of age, male Sprague-Dawley rats were subjected to removal of their vomeronasal organ (VNO) complex, a sham-VNO ablation or large electrolytic lesions aimed at the pyriform cortex or corticomedial nuclei of the amygdala. Other rats were infused with (1) 7.5% ZnSO4, a treatment that destroys the olfactory neuroepithelium, (2) 0.09% saline, or (3) air in each external nare every 4 days; rats from each treatment condition were assigned either to a long (LD 14:10) or short (LD 8:16) day lighting regimen and were autopsied at 90 days of age. Seminal vesicle and paired testes weights did not differ significantly among long-day groups. Mean seminal vesicle and paired testes weights were decreased only in short-day rats treated with ZnSO4. These results indicate that the VNO does not mediate the effects of photoperiod on rat reproduction. Olfactory information, not transduced by the amygdala, or nonsensory components of the olfactory bulbs appear to mask photoperiodism in intact rats.

Amygdala↗