Correlation between Changes in Stress-Induced Corticosterone Secretion and GR mRNA Levels

The current study was conducted to determine the potential relationship between stress-induced corticosterone secretion and corticosteroid receptor mRNA levels after 5 days of intermittent stress. In particular, we were interested in the rate at which animals terminate a stress response, and how this termination may be altered by repeated stress. Adult male Sprague-Dawley rats were subjected to either 5 days of restraint stress or 5 days of an unpredictable stress paradigm. Restraint-stress induced corticosterone secretion was measured on Days 1 and 5 in both groups, and animals were killed on Day 6. Glucocorticoid receptor (GR), and mineralocorticoid (MR) mRNA levels were determined using in-situ hybridization techniques. Five days of restraint stress caused an habituation of the plasma corticosterone response to stress measured 60 and 90 min post-stress initiation; this pattern of corticosterone secretion was not observed in the animals subjected to unpredictable stress. Five days of either stress paradigm did not alter MR mRNA levels measured within the hippocampus or GR mRNA levels within the hippocampus or the medial parvocellular division of the paraventricular nucleus of the hypothalamus (mpPVN). However, an individual's GR mRNA levels measured within the CA1/2 region of the hippocampus and the mpPVN were significantly correlated with the degree of habituation of the corticosterone response to stress measured on Day 5. This suggests that an increase in the rate of termination of the stress response and levels of GR within the hippocampus and mpPVN may be functionally related.     

Classroom behavior and the academic progress of learning disabled students

A total of 43 learning disabled (LD) students who were identified in grades 1–3 were followed up in their second year of special education services. Teachers completed the Classroom Behavior Inventory (CBI) for each LD student and for randomly selected classmates, and both groups of students were observed with the SCAN system in regular classroom settings. Group differences in teacher perceived task orientation, independence, and verbal expressiveness replicated previous findings with the CBI for this LD sample. SCAN observations partially replicated previous results in that LD children interacted with teachers more often than classmates. Multiple regression analyses indicated that both measures of behavior were predictive of reading achievement during year 1 when the LD children were identified, and that the CBI predicted academic progress from one year to the next. Both teacher ratings and observational evidence converged on the importance of task-oriented behavior, independent functioning, and socially appropriate behavior in understanding the poor achievement of LD students.     

Identifying Children in Middle Childhood Who Are at Risk for Reading Problems

The purpose of this study was to identify and evaluate a universal screening battery for reading that is appropriate for older elementary students in a response to intervention model. Multiple measures of reading and reading correlates were administered to 230 fourth-grade children. Teachers rated children's reading skills, academic competence, and attention. Children were classified as not-at-risk or at-risk readers based on a three-factor model reflecting reading comprehension, word recognition/decoding, and word fluency. Predictors of reading status included group-administered tests of reading comprehension, silent word reading fluency, and teacher ratings of reading problems. Inclusion of individually administered tests and growth estimates did not add substantial variance. The receiver-operator characteristic curve analysis yielded an area under the curve index of 0.90, suggesting this model may both accurately and efficiently screen older elementary students with reading problems.