John P. Lombardo

A Comparison of Molecular Alterations in Environmental and Genetic Rat Models of ADHD: a pilot study

Attention deficit hyperactivity disorder (ADHD) is the most common neurobehavioral disorder in school‐aged children. In addition to genetic factors, environmental influences or gene × environmental interactions also play an important role in ADHD. One example of a well studied environmental risk factor for ADHD is exposure to polychlorinated biphenyls (PCBs). In this study, we investigated whether the well‐established genetic model of ADHD based on the spontaneously hypertensive rat (SHR) and a well established PCB‐based model of ADHD exhibited similar molecular changes in brain circuits involved in ADHD. The brains from 28 male rats (8 SHR, 8 Sprague–Dawley (SD) controls, 8 Wistar/Kyoto (WKY) controls, and 4 PCB‐exposed SD rats) were harvested at postnatal days (PNDs) 55–65 and RNA was isolated from six brain regions of interest. The RNA was analyzed for differences in expression of a set of 308 probe sets interrogating 218 unique genes considered highly relevant to ADHD or epigenetic gene regulation using the Rat RAE230 2.0 GeneChip (Affymetrix). Selected observations were confirmed by real‐time quantitative RT‐PCR. The results show that the expression levels of genes Gnal, COMT, Adrbk1, Ntrk2, Hk1, Syt11, and Csnk1a1 were altered in both the SHR rats and the PCB‐exposed SD rats. Arrb2, Stx12, Aqp6, Syt1, Ddc, and Pgk1 expression levels were changed only in the PCB‐exposed SD rats. Genes with altered expression only in the SHRs included Oprm1, Calcyon, Calmodulin, Lhx1, and Hes6. The epigenetic genes Crebbp, Mecp2, and Hdac5 are significantly altered in both models. The data provide strong evidence that genes and environment can affect different set of genes in two different models of ADHD and yet result in the similar disease‐like symptoms.

AROCLOR 1242 INHALATION AND INGESTION BY SPRAGUE-DAWLEY RATS

PCBs have been considered to be almost nonvolatile and insoluble in water. However, recent studies have shown the importance of their slight solubility in water and capability to enter the atmosphere and disperse throughout the global environment. This preliminary study was designed to measure uptake and observe any physiological changes in Sprague-Dawley rats. The PCB product Aroclor 1242 is the major pollutant of the Hudson River, NY, and New Bedford Harbor, MA. The rats were exposed for 30 d to 0.9 microg/m3 via inhalation and 0.436 microg/g (ppm) in the food. The inhalation of PCBs gave a greater PCB uptake than ingestion. Both routes of administration caused significant serum thyroid hormone elevations. Histopathologic changes were observed in the urinary bladder, thymus, and the thyroid after both exposure regiments. Rearing and ambulation were significantly decreased in both exposure regiments in an open field behavior test.

The relationship of self-disclosure to personality, adjustment and self-actualization

This study tested the hypothesis that a high level of self-disclosure is indicative of psychological adjustment and self-actualization. The self-disclosure scale, Social Avoidance and Distress, Fear of Negative Evaluation, Alienation and Repression-Sensitization scales were administered to 60 Ss. The results for all scales indicated that a high level of disclosure was associated with adjustment as measured by these scales. A second group of 94 Ss completed the self-disclosure scale and the Personal Orientation Inventory, a measure of self-actualization. The results indicated that high disclosers compared to low disclosers had achieved a higher level of self-actualization. That is, there were significant correlations between self-disclosure and measures of self-actualization such as Time Competence, Internal Support, Existentiality, Self-Acceptance and Capacity for Intimate Contact.

Self-disclosure: Intimate and nonintimate disclosures to parents and best friends as a function of bem sex-role category

Thirty-two androgynous, traditional, and undifferentiated males and females (N/it=192) completed a 6-item self-disclosure questionnaire containing 30 intimate and 30 nonintimate items. The targets were father, mother, and best male and female friends. Analyses of both intimate and nonintimate items indicated that amount of self-disclosure was related to sex role and not gender. Typical male-female differences in self-disclosure were not found because (a) androgynous males disclosed at significantly higher levels than traditional and undifferentiated males to most targets; (b) undifferentiated males and females disclosed significantly less than their androgynous and traditional counterparts. Intimate self-disclosure by androgynous males to father, and nonintimate disclosure by androgynous females to father, were particularly high. Both findings suggest a unique role for fathers in the development of androgynous persons. Androgynous females reported higher disclosure to best male friend than to mother. This is counter to the traditional female pattern and is interpreted as representing a greater degree of distancing from mother and openness to peers.

FAILURE AND ITS RELATIONSHIP TO THE SOCIAL FACILITATION EFFECT: EVIDENCE FOR A LEARNED DRIVE INTERPRETATION OF THE SOCIAL FACILITATION EFFECT

Social facilitation theory states that an audience functions as a conditioned stimulus for generalized drive and that this drive effect is learned through classical conditioning. In the present study an attempt was made to condition classically an aversive drive to an audience by having a subject fail a task in front of an audience. A sample of 61 subjects took part in a 2 × 2 factorial design. Half of the subjects did not perform a first task but only a complex motor task. Half of these subjects performed in the presence of an audience, half without an audience present. Of those subjects exposed to failure on the first task, half performed a second complex motor task in the presence of the same audience. Results indicated that performance of subjects who failed a first task in the presence of an audience and then performed the second task in the presence of that audience was significantly poorer than all of the other groups. The findings were taken as evidence that the social facilitation effect may be based on an aversive learned drive.

The effect of failure and the nature of the audience on performance of a complex motor task.

Social facilitation theory states that an audience functions as a conditioned stimulus for generalized drive and that this drive effect is learned through classical conditioning. In the present study an attempt was made to classically condition an aversive drive to an audience by having a subject fail a task in front of an audience. A sample of 72 subjects (12 per group) took part in a 3 × 2 factorial design. Half of the subjects were exposed to failure in front of an audience on a first task. These subjects then performed a second complex motor task in front of the same audience who were described as either experts on this second task or as students who were interested in the task (non-expert audience). No differences in performance were found between those groups that had failed a first task and those that had not. However, significant differences in performance were found between the no-audience control, non-expert audience, and expert audience conditions.

Inhalation of Polychlorinated Biphenyls (PCB) Produces Hyperactivity in Rats.

Attention deficit hyperactivity disorder (ADHD) is a serious behavioral syndrome seen in children, and more common in males than females. There is increasing evidence that prenatal and/or early life exposure to persistent organic pollutants (POP) such as polychlorinated biphenyls (PCB) is associated with increased risk of ADHD occurrence. While PCB exposure is usually attributed to ingestion of contaminated food, recent reports of elevated PCB concentrations in indoor air, especially in schools, raised concern regarding inhalation as an important route of exposure to PCB with consequent effects on neurobehavior. The effects of exposure to air contaminated with Aroclor 1248 or contaminated sediment (SED) from the St. Lawrence River were examined on operant behavior of male and female Sprague-Dawley rats. Data showed that relative to controls, vapor-phase inhalation of PCB, whether from blowing air over Aroclor 1248 or from blowing air over sediment contaminated with PCB, resulted in hyperactivity and impatience in rats, more pronounced in males than females. These results are consistent with the hypothesis that inhalation of PCB may contribute to behavioral abnormalities in children.

The Relationship of Internality-Externality, Self-Acceptance, and Self-Ideal Discrepancies.

Internals (n=35) and externals (n=38) responded to Rotters (12) I-E scale under two sets of instructions: standard (as the kind of persons they really were) and ideal-self instructions (as if they were the types of persons they would like to be) and the self-acceptance questionnaire (4). Results indicated (a) on both instruments the discrepancy between real and ideal-self was significantly larger in externals: (b) the external ideal-self includes an internal locus of control; (c) a significant discriminatory factor between internals and externals is their perceived control over their own destiny and not social institutions. The results were discussed in terms of the relationship of externality to maladjustment, neuroticism, and possible causes for this relationship.

Perceived Locus of Control and Attraction as a Function of Locus of Control Orientation

Several studies have found that ones locus of control orientation affects perceived locus of control. However, the nature and extent of this influence has not been consistent. In this investigation internal and external subjects interacted with strangers whose responding was characteristic of internality or externality (resistence or yielding to attitude change), and perceived locus of control and attraction were assessed. Contrary to the previous research, ones own locus of control did not affect perception of locus of control. In addition, attraction was found to be a function of the strangers resistence or yielding to attitude change rather than personality similarity.

Modification of Self-Disclosing Behaviors Through Modeling and Vicarious Reinforcement

Modeling techniques were used to model moderate disclosure to high and low disclosers. Eighty female undergraduates (40 low disclosers and 40 high disclosers) listened to a model select items that were rated as moderate disclosures for discussion. Two modeling conditions were employed; in one condition the model was reinforced by the E (vicarious reinforcement), in the second condition the model was not reinforced. Two control conditions, one with the model present, the other with the model absent were also included. The results of two separate 2 X 4 X 2 repeated measures, hierarchical analyses of variance on the subject distance from modeled intimacy, and the number of moderate items selected on pre- and posttests, indicated that both modeling conditions were successful in producing moderation of self-disclosure.