Impaired memory and olfactory performance in NaSi-1 sulphate transporter deficient mice

In the present study, NaSi-l sulphate transporter knock-out (Nas1-/-) mice, an animal model of hyposulphataernia, were examined for spatial memory and learning in a Morris water maze, and for olfactory function in a cookie test. The Nas1-/- mice displayed significantly (P < 0.05) increased latencies to find an escape platform in the reversal teaming trials at 2 days but not 1 day after the last acquisition trial in a Morris water maze test. suggesting that Nas1-/- mice may have proactive memory interference. While the wild-type (Ncis1+/+) mice showed a significant (P < 0.02) decrease in time to locate a hidden food reward over four trials after overnight fasting, Nas1-/- mice did not change their performance, resulting in significantly (P < 0.05) higher latencies when compared to their Nas1+/+ littermates. There were no significant differences between Nas1-/- and Nas1+/+ mice in the cookie test after moderate food deprivation. In addition, both Nas1-/- and Nas1+/+ mice displayed similar escape latencies in the acquisition phase of the Morris water maze test, suggesting that learning, motivation, vision and motor skills required for the task may not be affected in Nas1-/- mice. This is the first study to demonstrate an impairment in memory and olfactory performance in the hyposulphataemic Nas1-/- mouse. (c) 2004 Elsevier B.V. All rights reserved.

Adolescent tobacco-related associative memory: a cross-sectional and contextual analysis

Tobacco use is prevalent in adolescents, and understanding factors that contribute to its uptake and early development remains a critical public health priority. Implicit drug-related memory associations (DMAs) are predictive of drug use in older samples, but such models have little application to adolescent tobacco use. Moreover, extant research on memory associations yields little information on contextual factors that may be instrumental in the development of DMAs. The present study examined (a) the degree to which tobacco-related memory associations (TMAs) were associated with concurrent tobacco use and (b) the extent to which TMAs mediated the association of peer and self-use. A sample of 210 Australian high school students was recruited. Participants completed TMA tasks and behavioral checklists designed to obscure the tobacco-related focus of the study. Results showed that TMAs were associated with peer use, and TMAs predicted self-use. We found no evidence that TMAs mediated the association of peer and self-use. Future research might examine the emotive valence of implicit nodes and drinking behavior. The results have implications for testing the efficacy of consciousness-raising interventions for adolescents at risk of tobacco experimentation or regular use.

Longitudinal associations between children's phonological processing abilities, ADHD-like behaviour ratings and early reading develpment

The current study examined the contribution of phonological processing abilities and ADHD-like behaviours to first-grade word reading ability. 136 children were tested at the beginning and end of first grade. At both times, teachers rated children on hyperactive, inattentive, and oppositional behaviour. Children were given tests of letter knowledge at T1 and tests of word reading, phonological sensitivity, phonological memory, rapid automatised naming, and vocabulary at T1 and T2. Regression analyses revealed that, of the behavioural measures, inattention made the strongest contribution to T2 reading, even after controlling for the effects of T1 reading, hyperactivity, and oppositional behaviour. Hyperactivity did not explain variance in T2 reading once the effect of inattention was controlled. Inattention predicted 4.7% independent variance in T2 word reading ability, even after the effects of T1 reading, vocabulary, and phonological processing were controlled. Although phonological processing predicted 9.3% independent variance in T2 word reading, even after the effects of reading, vocabulary, and inattention were controlled, the effects of phonological processing may have been partly mediated by inattention. This research indicates that inattention contributes to the prediction of early reading development in unselected populations, and that this influence is independent of other key cognitive predictors of reading ability.