Hyperactivity and Learning Deficits in Transgenic Mice Bearing a Human Mutant Thyroid Hormone β1 Receptor Gene

Resistance to thyroid hormone (RTH) is a human syndrome mapped to the thyroid receptor β (TRβ) gene on chromosome 3, representing a mutation of the ligandbinding domain of the TRβ gene. The syndrome is characterized by reduced tissue responsiveness to thyroid hormone and elevated serum levels of thyroid hormones. A common behavioral phenotype associated with RTH is attention deficit hyperactivity disorder (ADHD). To test the hypothesis that RTH produces attention deficits and/or hyperactivity, transgenic mice expressing a mutant TRβ gene were generated. The present experiment tested RTH transgenic mice from the PV kindred on behavioral tasks relevant to the primary features of ADHD: hyperactivity, sustained attention (vigilance), learning, and impulsivity. Male transgenic mice showed elevated locomotor activity in an open field compared to male wild-type littermate controls. Both male and female transgenic mice exhibited impaired learning of an autoshaping task, compared to wild-type controls. On a vigilance task in an operant chamber, there were no differences between transgenics and controls on the proportion of hits, response latency, or duration of stimulus tolerated. On an operant go/no-go task measuring sustained attention and impulsivity, there were no differences between controls and transgenics. These results indicate that transgenic mice bearing a mutant human TRβ gene demonstrate several behavioral characteristics of ADHD and may serve a valuable heuristic role in elucidating possible candidate genes in converging pathways for other causes of ADHD.     

Teaching the Introduction to Religions: Religious Pluralism in a Post-Colonial World

Taking seriously the implications of post-colonial theory, the authors revisit the introductory course (normally “World Religions”) as a course on the plurality of religions in contemporary U.S. culture. They explain the structure of the course, and discuss practical and ethical issues around student field visits to learn about other religions.     

Dysnomia in Alzheimer's disease: an evaluation of neurobehavioral subtypes.

The relative influence of perceptual and semantic features on naming performance was investigated with reference to the neurobehavioral profiles displayed by patients with Alzheimer's disease (AD). Forty-one patients were classified as manifesting a verbal, visual, or global subtype based upon their pattern of neuropsychological functioning. Perceptual characteristics of to-be-named pictures were varied by manipulating the amount of line detail, whereas semantic qualities were varied by altering word frequency norms. All AD subtypes were less accurate than normal elderly controls in naming low frequency pictures. Patients and controls took longer to name low frequency and high complexity pictures, and this effect was comparable across the AD groups. Patients with predominantly visual deficits were significantly slower in naming than controls, and those with verbal impairments made a higher proportion of semantic naming errors when compared to patients displaying visual or severe global impairments. These results suggest that deficits in semantic processing contribute to naming dysfunction in AD, and they highlight the importance of examining dissociations among neurobehavioral subtypes.     

Father identification,achievement, and occupational behavior of rural youth: One year follow-up

Rural economically deprived adolescent males, who had been previously surveyed as high school seniors concerning their post-high school plans, were surveyed again 1 yr later concerning their present occupational status and feelings of personal satisfaction. The Ss had been divided in an earlier study into two groups, low identification males (LIM) and high identification males (HIM) based upon independent evaluators' judgments of the adequacy of their fathers as identification models. Each group's responses to the survey were compared. The results indicate that there are no statistically significant differences between the two groups on the variables of satisfaction, having received counseling from others and optimism about the future. There are statistically significant differences between the current occupational status and future occupational plans of the two groups.     

Selective phonemic and semantic coding in short-term recall

Probed recall of targets from six-word sequences containing either phonemically similar, semantically similar, or control (i.e., unrelated phonemically and semantically) stimuli was compared under two conditions of encoding. For the semantic encoding condition, in which all cues provided category information about targets to be recalled, semantic similarity interference effects and phonemic similarity facilitation effects were demonstrated. In the phonemic encoding condition, in which all targets were cued by words which rhymed with them, only phonemic similarity interference effects were found. These results were taken to provide further evidence contradictory to the coding-based dichotomization of primary and secondary memory, and to reflect the importance of selective coding strategies induced by task requirements as determinants of interference effects in short-term recall.