Muscimol diffusion after intracerebral microinjections: a reevaluation based on electrophysiological and autoradiographic quantifications

Intracerebral muscimol injection is widely used to inactivate discrete brain structures during behavioral tasks. However, little effort has been made to quantify the extent of muscimol diffusion. The authors report here electrophysiological and autoradiographic results obtained after muscimol injection (1 microg/microl) either into the nucleus basalis magnocellularis (0.1-0.4 microl) or into the thalamic reticular nucleus (RE, 0.05-0.1 microl). In 52 rats, multiunit recordings were collected either in the RE or in the auditory thalamus during the 2 h following muscimol injection. Decreases in neuronal activity were observed up to 3 mm from the injection site; their time of occurrence was a function of the distance between the injection and recording sites. Because these decreases cannot be explained by physiological effects, they likely reflected muscimol diffusion up to the recording sites. Autoradiographic studies involved 25 rats and different experimental conditions. Optical density (OD) measures indicated that after a survival time of 15 min, a 0.05 microl injection produced a labeled area of 5.25 mm(2) at the injection site and a rostrocaudal labeling of 1.7 mm. Increasing the survival time to 60 min, or increasing the injected volume to 0.1 microl, systematically led to a larger labeled area at the injection site (8-12 mm(2)) and to a larger rostrocaudal diffusion (2.0-2.5 mm). Direct quantifications of radioactivity by a high-resolution radioimager validated the OD measures and even indicated a larger muscimol diffusion (up to 3.25 mm). Thus, these data point out that muscimol diffusion after intracerebral microinjection is larger than usually supposed. The relationships between these results and those obtained in behavioral studies are discussed.     

Comparison of the function of exchange in couples of similar and differing physical attractiveness

Couples (22 young, married, 18 young unmarried) completed the Exchange Orientation Scale, which measures how much individuals believe equality of exchange should characterize their social relationships, as well as the Norman Personality Trait Scale, which gives measures for the self and ideal-self. Couples also rated their sexual satisfaction, their partners' physical attractiveness, their own attractiveness, and had their photographs evaluated for attractiveness by disinterested raters. Subgroups were formed of physically attractive couples, couples in which the members were of disparate attractiveness, and couples in which the individuals perceived themselves as equal to their partners in attractiveness or as inferior. In accordance with exchange theory, the hypotheses were (1) unmarried men would show higher exchange scores than married men, (2) attractive men in disparately attractive couples would show greater exchange scores than attractive men in both-attractive couples, (3) attractive members of disparately attractive couples would possess lower self-acceptance and (4) experience greater sexual satisfaction than attractive members of both-attractive couples. Results supported all hypotheses in varying extents.     

Tribal aspects of postmodern consumption research: the case of French in‐line roller skaters

Tribes constitute a research focus for postmodern consumer research and an alternative way of targeting marketing action. Consumers are supposed to value the goods and services which, through their linking value, permit and support social interaction of the communal type, products or services that support AB and not the fact of being A or B. This paper seeks to explore current developments in postmodern consumer research in terms of methods used to identify tribes and in terms of approaches used to elaborate an offer which is capable of supporting tribal rites and to capitalise, at a brand image level, on these tribal phenomena. Copyright © 2001 Henry Stewart Publications.     

Responding to Evil

In this paper, I argue that moral and institutional evils, even though they are all contingent, are so pervasive and persistent that there is no practical way of responding to them that would lead eventually to the eradication of all of them. Instead, our practical task is to respond to these evils in ways that respect both the basic capabilities and their associated vulnerabilities that are constitutive of each human being. To do this most effectively, one should offer unconditional forgiveness to the perpetrators of evil. The attitude that can best underpin this forgiveness is one of a properly understood indefeasible hope, a hope that always insists that each person is of greater worth than whatever he or she does.     

Verbal memory compensation: application to left and right temporal lobe epileptic patients

This study investigates the compensatory impact of cognitive aids on left and right temporal lobe epileptic patients suffering from verbal memory disorders, who were candidates for surgery. Cognitive aids are defined in the levels-of-processing framework and deal with the depth of encoding, the elaboration of information, and the use of retrieval cues. Results indicate differential compensatory impact for left and right epileptic patients and are discussed according to the HERA model and the compensation framework.     

Personal need for structure and creative performance: the moderating influence of fear of invalidity

Previous research has suggested that personal need for structure (PNS) is negatively related to creative performance. In this article, it is argued that this relation, in fact, depends on another personality variable: personal fear of invalidity (PFI). When PFI is high, PNS should indeed be negatively associated with creativity. However, PNS should be positively associated with creativity when PFI is low, because this combination enables people to take a structured approach to creative tasks and this can be helpful to overcome their reliance on conventional and accessible task strategies. In four studies, this hypothesis is tested using different measures of creative performance. The expected interaction effect is found for measures of ideational fluency and measures of originality but not for measures of flexibility. Moreover, it is shown that the interaction effect between PNS and PFI is mediated by perseverance within thought categories.     

Suchttherapie bei abhängigen Ärzten

Background

International studies indicate an increased incidence of substance abuse disorders among physicians. This article investigates specific variables in the work field and describes existing treatment programs.

Patients and methods

In a cross-sectional study 107 physicians with and 468 without substance abuse disorders were compared. Two highly developed treatment programs in Germany and Canada are described.

Results

The high work-load associated with the medical work environment leads to reduced performance and social isolation. Treatment programs for addicted physicians work with the concept of ?help before restriction“. The abstinence rate of the 5-year Canadian program is over 90%.

Conclusions

As a form of prevention, medical students should be systematically informed about work-related stress in the medical profession. Structured treatment programs should be implemented nationwide. The expert team ?Risk of addiction in physicians“ of the German Addiction Foundation, whose members are authors of this article, may be a small step in this direction.     

Foster Parents’ Involvement in Authoritative Parenting and Interest in Future Parenting Training

We surveyed 191 Southwest Ohio foster parents regarding their involvement in authoritative parenting and interest for additional parenting education. Our results showed that most respondents reported using an authoritative parenting style and were interested in receiving future training. Involvement in authoritative parenting differed significantly based on level of education and number of years as a foster parent. Foster parents with a college degree or higher were significantly more involved in authoritative parenting than foster parents with a high school diploma or less. Those who had been a foster parent for greater than five years were significantly more likely than those who been a foster parent for five years or less to use authoritative parenting and desire future training in authoritative parenting.     

ERPs associated with visual duration discriminations in prefrontal and parietal cortex

An event-related potentials (ERP) study was undertaken to examine the role of prefrontal and parietal association cortices on selective attention and short-term memory functions in a duration discrimination task. Subjects performed better when discriminating the first stimulus relative to the second and not the reverse. Two contingent negative variations (CNV) were obtained for each stimulus duration at prefrontal regions, as well as two P300s at parietal regions. The CNV(S1) component recorded during the first stimulus (S1) appeared to be involved in selective attention at bilateral sites, while the P300(S1) component in the left hemisphere may be implicated in retaining it. The CNV(S2) wave, displayed during the second stimulus (S2), at bilateral sites and the right-sided P300(S2) wave seem to be implicated in working memory. The results indicate that recorded activity at prefrontal and parietal association cortices is tightly linked to task parameters and behavioral performances.