Adult foreign language acquisition is challenging, and the degree of success varies among individuals. Anatomical differences in brain structure prior to training can partly explain why some learn more than others. We followed a sample of conscript interpreters undergoing intense language training to study learning-related changes in white-matter microstructure (FA, MD, RD and AD) and associations between differences in brain structure prior to training with acquired language proficiency. No evidence for changes in white matter microstructure relative to a control group was found. Starting values of RD, AD and MD were positively related to final test scores of language proficiency, corroborating earlier findings in the field and highlighting the need for further study of how initial brain structure influences and interacts with learning outcomes.

Quetiapine, originally developed as an antipsychotic, demonstrates efficacy in clinical studies of schizophrenia, bipolar mania and depression, major depressive disorder and generalized anxiety disorder. This broad spectrum of efficacy was not predicted from the preclinical pharmacology of quetiapine. Binding studies in vitro show that quetiapine and its major active human metabolite, norquetiapine, have moderate to high affinity for dopamine D2 and serotonin 5-HT2A receptors, while norquetiapine alone has high affinity for the norepinephrine transporter (NET). This positron emission tomography (PET) study measured NET occupancy in human subjects treated with extended-release quetiapine (quetiapine XR) at doses relevant in the treatment of depression. PET measurements using the specific NET radioligand (S,S)-[18F]FMeNER-D2 were performed before and after quetiapine XR treatment at 150 and 300 mg/d for 6–8 d in nine healthy males (aged 21–33 yr). Regions of interest were defined for the thalamus, using the caudate as reference region. NET occupancy was calculated using a target:reference region ratio method. Plasma concentrations of quetiapine and norquetiapine were monitored during PET measurements. Following quetiapine XR treatment, the mean NET occupancy in the thalamus was 19 and 35%, respectively, at quetiapine XR doses of 150 and 300 mg/d. The estimated plasma concentration of norquetiapine corresponding to 50% NET occupancy was 161 ng/ml. This is the first demonstration of NET occupancy by an antipsychotic in the human brain. NET inhibition is accepted as a mechanism of antidepressant activity. NET occupancy may therefore contribute to the broad spectrum of efficacy of quetiapine.

A large body of evidence supports the idea that a common fronto-parietal network is activated across a range of diverse cognitive functions. Jung & Haier's (J&H's) review demonstrates a very similar pattern of activity, which correlates with individual differences in intelligence. We propose that these converging lines of evidence are best interpreted as a general role of the fronto-parietal network in integration and control.

Background: Early diagnosis of Alzheimer's disease (AD) is critical for adequate treatment and care. Recently it has been shown that functional magnetic resonance imaging (fMRI) can be important in preclinical detection of AD. The purpose of this study was to examine possible differences in memory-related brain activation between persons with high versus low risk for AD. This was achieved by combining a validated neurocognitive screening battery (the 7-minutes test) with memory assessment and fMRI. Methods: One hundred two healthy community-living persons with subjective memory complaints were recruited through advertisement and tested with the 7-minutes test. Based on their test performance they were classified as having either high (n = 8) or low risk (n = 94) for AD. Six high-risk individuals and six age-, sex-, and education-matched low-risk individuals were investigated with fMRI while engaged in episodic memory tasks. Results: The high-risk individuals performed worse than low-risk individuals on tests of episodic memory. Patterns of brain activity during episodic encoding and retrieval showed significant gourp differences (p < .05 corrected). During both encoding and retrieval, the low-risk persons showed increased activity relative to a baseline condition in prefrontal brain regions that previously have been implicated in episodic memory. By contrast, the high-risk persons did not significantly activate any prefrontal regions, but instead showed increased activity in visual occipito-temporal regions. Conclusion: Patterns of prefrontal brain activity related to episodic memory differ between persons with high versus low risk for AD, and lowered prefrontal activity may predict subsequent disease.

Several types of neuroreceptors are of interest with respect to antipsychotic activity, in particular the D2, D1, and 5-HT2 receptors. Among currently prescribed antipsychotic drugs, some have an affinity for a broad range of neuroreceptors, while others are more selective for the D2 receptor (Hytell et al, 1985). The most widely accepted hypothesis of neuroleptic drug action is that antipsychotic effects are mediated by a blockade of the dopamine receptors (Carlsson & Lindqvist, 1963; van Rossum, 1966; Creese et al, 1976; Seeman et al, 1976; Peroutka & Snyder, 1980). This hypothesis has been supported by consistent findings of high D2 receptor occupancy in positron emission tomography (PET) studies of patients treated with antipsychotic drugs (Farde et al, 1986; Smith et al, 1988; Baron et al, 1989). At the same time, the risk of extrapyramidal side-effects (EPS) seems particularly high in patients with occupancy above 80% (Farde et al, 1992) (Fig. 1).