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Biomedical subjects

S L Bieber

Publications and source records attributed to S L Bieber.

11 recordsLinked to original sources
PubMed1999

Differential effects of intraventricular injections of tachykinin NK1 and NK3 receptor agonists on normal and sham drinking of NaCl by sodium-deficient rats.

The effects of lateral ventricular injections of succinyl-[Asp6, N-Me-Phe8]-substance P (SENK; 25, 100, 200 ng), a tachykinin NK3 receptor agonist, and [Sar9, Met(O2)11]-substance P (Sar Met; 100, 200 ng), an NK1 receptor agonist, on normal (gastric fistula closed) and sham drinking (gastric fistula open) of hypertonic NaCl by sodium-deficient rats were compared. Intraventricular injections of Sar Met had no effect on NaCl intake in either condition. Injections of 100 ng and 200 ng SENK caused an equal suppression of NaCl intake in the 2 fistula conditions. The latency to drink was not affected, but the initial lick rate was significantly lower and decayed more rapidly after 100 ng SENK than after saline or 25 ng SENK. The results show that (a) the tachykinin subtypes are not equally involved in the control of need-induced salt intake; (b) negative feedback from the stomach and distal gastrointestinal tract is not required for intraventricular injections of SENK to suppress sodium appetite; (c) the activation of NK3 receptors decreases the oral excitatory influence of hypertonic NaCl in sodium-deficient rats.

Animals↗
PubMed1997

The effects of acculturative stress on incarcerated Alaska Native and non-Native men.

The relationship of acculturative status, acculturative stress, and interpersonal violence was examined in a study consisting of 73 incarcerated Alaska Native and non-Native men. The instruments used were the Acculturation Scale, Padilla SAFE Acculturative Stress Measure, Conflict Tactics Scale, Rorschach test, and the Perceived Stress Scale. Results found few inmates in the marginal group and no relationship between acculturative status and acculturative stress. Native inmates had significantly higher levels of acculturative stress than non-Native inmates, and other measures of stress did not discriminate between these two groups. Only non-Native inmates had higher levels of interpersonal violence related to acculturative stress, but their experience of acculturative stress was compounded by perceived, chronic, and situational stress. Apparently, non-Native inmates' feelings of acculturative stress are actually a sense of being discriminated against unrelated to their ethnicity. Bicultural inmates had significantly higher levels of violence than assimilated inmates did. For these inmates, acculturative stress is not the link between cultural conflict and interpersonal violence, but attempting to be a part of both cultures may be. The problem for these inmates seems to be in adapting to their cultural orientation, not in the orientation itself. While in prison, many native men seem to cope by renewing their cultural and spiritual practices, which may be providing them with a cultural identity they did not possess before incarceration. Acculturative status may need to be viewed as a continuum and a conscious choice. Implications for treatment and further research are discussed.

Acculturation↗
PubMed1996

Parental abusive versus supportive behaviors and their relation to hostility and aggression in young adults.

The relation of parental support to abuse has rarely been considered in research on the sequelae of childhood abuse in adulthood. In this study, using the Exposure to Abusive and Supportive Environments Parenting Inventory (EASE-PI), young adults who reported higher emotionally abusive parenting (EA) consistently reported significantly lower love and support from both parents. The relation between physically abusive parenting (PA) and love/support depended upon gender of parent and child. EA was significantly related to higher hostility and higher aggression, as measured by the Buss-Durkee Hostility Inventory, for both men and women, and to reports of physical fights within the family, for women only. PA was significantly related to higher aggression but not higher hostility. Lower support by fathers, but not by mothers, was significantly related to higher hostility. However, lower support of daughters by mothers was significantly related to increased physical fights in the family. Results indicate that less severe abusive behaviors, especially EA, may have detrimental outcomes of hostility and aggression and that supportive behaviors by both mothers and fathers may be important factors in the outcome.

Adolescent↗
PubMed1996

Personality styles and dynamics of Alaska Native and nonnative incarcerated men.

The Rorschach and Million Clinical Multiaxial Inventory-II (MCMI-II) were used to examine personality styles and dynamics of 73 incarcerated Alaska Native and nonnative men. There were clear differences between native and nonnative inmates on both the MCMI-II and the Rorschach. Also, when the participants were separated into bicultural, assimilated, and traditional groups, the bicultural group had the most difficulties in coping and in interpersonal relationships. The results of this study suggest that the profile for offenders is not the same for Alaska natives and nonnatives. Culture and cultural styles may contribute to create a significantly different type of "criminal personality" seen in forensic settings.

Acculturation↗
PubMed1994

Perceptions of mothers' and fathers' abusive and supportive behaviors.

Young adults' perceptions of parenting behaviors were explored, specifically with regard to the issue of how perceptions may be affected by gender of parent, child, or observer. Ratings of psychologically (emotionally), physically, and sexually abusive behaviors and ratings of love/support, promotion of independence, and positive modeling/fairness were obtained for mothers and fathers as well as daughters and sons. When father was the referent, female subjects rated the behaviors as more emotionally, physically, and sexually abusive than male subjects did. When mother was the referent, gender of subject and gender of child interacted, with female subjects rating the behaviors as more abusive when done to sons than male subjects did. Male and female subjects agreed that behaviors representing love/support and fairness were highly supportive when done by fathers. When done by mothers, female subjects rated love/support behaviors as more supportive for sons than male subjects did. Results indicated that gender of parent, child, and observer may affect young adults' perceptions of parental abusiveness and supportiveness.

Adult↗
PubMed1988

The organization of taste sensibilities in hamster chorda tympani nerve fibers.

Electrophysiological measurements of nerve impulse frequencies were used to explore the organization of taste sensibilities in single fibers of the hamster chorda tympani nerve. Moderately intense taste solutions that are either very similar or easily discriminated were applied to the anterior lingual surface. 40 response profiles or 13 stimulus activation patterns were considered variables and examined with multivariate statistical techniques. Three kinds of response profiles were seen in fibers that varied in their overall sensitivity to taste solutions. One profile (S) showed selectivity for sweeteners, a second (N) showed selectivity for sodium salts, and a third (H) showed sensitivity to salts, acids, and other compounds. Hierarchical cluster analysis indicated that profiles fell into discrete classes. Responses to many pairs of effective stimuli were covariant across profiles within a class, but some acidic stimuli had more idiosyncratic effects. Factor analysis of profiles identified two common factors, accounting for 77% of the variance. A unipolar factor was identified with the N profile, and a bipolar factor was identified with the S profile and its opposite, the H profile. Three stimulus activation patterns were elicited by taste solutions that varied in intensity of effect. Hierarchical cluster analysis indicated that the patterns fell into discrete classes. Factor analysis of patterns identified three common unipolar factors accounting for 82% of the variance. Eight stimuli (MgSO4, NH4Cl, KCl, citric acid, acetic acid, urea, quinine HCl, HCl) selectively activated fibers with H profiles, three stimuli (fructose, Na saccharin, sucrose) selectively activated fibers with S profiles, and two stimuli (NaNO3, NaCl) activated fibers with N profiles more strongly than fibers with H profiles. Stimuli that evoke different patterns taste distinct to hamsters. Stimuli that evoke the same pattern taste more similar. It was concluded that the hundreds of peripheral taste neurons that innervate the anterior tongue play one of three functional roles, providing information about one of three features that are shared by different chemical solutions.

Animals↗
PubMed1984

Joint and separate effects of estrogen and progesterone on responses of midbrain neurons to lordosis-controlling somatic stimuli in the female golden Syrian hamster.

Single midbrain neurons were examined for effects of ovarian hormone administration on responsiveness to an array of lordosis-controlling types of somatosensory stimuli in anesthetized, ovariectomized Syrian hamsters. Neuronal responses were recorded under four different hormonal treatment conditions: 1) estradiol benzoate (EB) followed by progesterone (P), 2) EB alone, 3) P alone, or 4) no hormone administration. Only the hamsters receiving both EB and P showed lordosis in a mating test immediately prior to preparation for recording. The joint administration of EB and P strongly facilitated unit responsiveness to lordosis-eliciting (e.g., lumbosacral tactile) forms of stimulation. The incidence of units showing sustained changes in firing of at least +/- 30% in response to these stimuli was highest in animals having received EB and P (69%) and lowest in those given P alone (37%), with the occurrence of responsive units significantly different across the four hormonal conditions. The magnitude of the median unit response to lordosis-trigger stimuli in hamsters given EB and P was significantly higher than unit responses in hamsters receiving either P alone or no hormone. Bilateral shoulders stimulation, a weak stimulus for lordosis elicitation, produced the most responses in units from animals given EB and P (42%) and the fewest in hamsters given EB alone (12%), with a significant difference in responsiveness across the hormonal conditions. The incidence of units responding exclusively to facial stimulation, which is strongly antagonistic to lordosis in behaving animals, was greatest in hamsters injected with P alone (22%) and least for cells from the animals given both EB and P (6%). The difference in unit responsiveness to this stimulus across the four hormone conditions was significant. Analysis of unit-response patterns by the multivariate technique of discriminant analysis revealed that neuronal responses to most stimuli, especially flanks, back, shoulders, and face, were differentially affected by the hormone treatments such that these response patterns could be used to identify the four hormonal conditions from which the neurons were sampled. In addition, the hormonal treatments were found to have influenced the incidence of accelerative or decelerative unit responses to somatic stimuli. Discriminant analysis of unit responses as a function of location of the cells within the midbrain showed that neurons in the tectum and central gray had response patterns highly distinguishable from each other as well as from those of cells in the central and ventromedial tegmental regions.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1983

Gustatory neuron types in hamster brain stem.

In general, mammalian taste neurons are broadly responsive to stimuli representing different taste qualities. In the hamster, this breadth of tuning increases systematically from peripheral to successively higher brain stem neurons. Some investigators have classified taste-responsive neurons into "best-stimulus" categories on the basis of which of the four basic stimuli (sucrose, NaCl, HCl, or quinine hydrochloride) elicits the maximum response. However, attempts by others to demonstrate the existence of taste neuron types in the chorda tympani nerve and medulla of the rat using hierarchical cluster analysis have not been successful, resulting in the conclusion that there are no neuron types in the rat gustatory system. The present study was designed to look at the question of neuron types in the hamster, a species with a broader range of gustatory sensitivities to anterior tongue stimulation. Responses of 30 neurons in the nucleus tractus solitarius (NTS) and 31 neurons in the parabrachial nuclei (PbN) of the hamster to an array of 18 stimulus compounds were recorded extracellularly. The similarities of the neural response profiles of these cells at each synaptic level were compared using multivariate statistical techniques. The possiblee grouping of cells on the basis of similarities in their response functions was examined with hierarchical cluster analysis, and the relationships among these response functions were examined with multidimensional scaling. The results of the cluster analysis suggested that at both the NTS and PbN, there are three clusters of neural response profiles. These three clusters of response profiles are characterized at both synaptic levels by their predominant sensitivity to 1) sucrose and other sweet-tasting compounds, 2) sodium salts, and 3) nonsodium salts and acids. Representation of these neurons in a two-dimensional space yielded three nonoverlapping groups of cells in both the NTS and PbN, corresponding to the three groups identified by the hierarchical cluster solution. Classification of taste neurons either by their best stimulus or by other criteria has been criticized on the grounds that it may constitute an arbitrary division of a continuous population of neurons. The techniques of numerical taxonomy, which take the cells' variability into account, also result in a grouping of taste cells into classes. These taxonomic classes agree in most instances (80% in NTS and 80.6% in PbN) to a best-stimulus classification. The failure of some investigators to find types of neural response profiles in the rat gustatory system may be the result of species differences in taste sensitivity as well as differences in the statistical procedures employed.

Acids↗