G protein–coupled receptors (GPCRs) are ubiquitous mediators of signaling of hormones, neurotransmitters, and sensing. The old dogma is that a one ligand/one receptor complex constitutes the functional unit of GPCR signaling. However, there is mounting evidence that some GPCRs form dimers or oligomers during their biosynthesis, activation, inactivation, and/or internalization. This evidence has been obtained exclusively from cell culture experiments, and proof for the physiological significance of GPCR di/oligomerization in vivo is still missing. Using the mouse luteinizing hormone receptor (LHR) as a model GPCR, we demonstrate that transgenic mice coexpressing binding-deficient and signaling-deficient forms of LHR can reestablish normal LH actions through intermolecular functional complementation of the mutant receptors in the absence of functional wild-type receptors. These results provide compelling in vivo evidence for the physiological relevance of intermolecular cooperation in GPCR signaling.

In Sweden, from 1985 through 1995, 40 fetuses at risk for congenital adrenal hyperplasia (CAH) were treated with dexamethasone (DEX) to prevent virilization of affected females. We report long-term effects on neuropsychological functions and scholastic performance of this controversial treatment. Prenatally treated children, 7 to 17 yr old, were assessed with standardized neuropsychological tests (A Developmental Neuropsychological Assessment and Wechsler Intelligence Scales for Children) and child-completed questionnaires measuring self-perceived scholastic competence (Self-Perception Profile for Children). A parent-completed questionnaire (Child Behavior Checklist/4-18 School Scale) was used to evaluate whether the treatment had any impact on the children's school performance. In addition, a child-completed questionnaire measuring social anxiety (The Social Anxiety Scale for Children-Revised) was completed by the prenatally treated children aged 8 to 17 yr (n = 21) and age- and sex-matched controls (n = 26). Of 40 DEX-treated children, 26 (median age, 11 yr) participated in the study. Thirty-five sex- and age-matched healthy children were controls. There were no between-group differences concerning psychometric intelligence, measures of cerebral lateralization, memory encoding, and long-term memory. Short-term treated, CAH-unaffected children performed poorer than the control group on a test assessing verbal working memory (P = 0.003), and they rated lower on a questionnaire assessing self-perception of scholastic competence (P = 0.003). This group also showed increased self-rated social anxiety assessed by The Social Anxiety Scale for Children-Revised (P = 0.026). Prenatally treated, CAH-affected children performed poorer than controls on tests measuring verbal processing speed, although this difference disappeared when controlling for the child's full-scale IQ. This study indicates that prenatal DEX treatment is associated with previously not described long-term effects on verbal working memory and on certain aspects of self-perception that could be related to poorer verbal working memory. These findings may thus question future DEX treatment of congenital adrenal hyperplasia. Therefore, we encourage additional retrospective studies of larger cohorts to either confirm or challenge the present findings.

Objectives: To investigate the long-term effects of prenatal treatment of congenital adrenal hyperplasia (CAH) with emphasis on behavioural problems and temperament.Design: A population-based long-term follow-up study of Swedish children at risk for virilising CAH, who had received treatment prenatally with dexamethasone (DEX). The questionnaire-based follow-up was performed when the children had reached school age.Methods: Standardised parent-completed questionnaires were used to evaluate adaptive functioning, behavioural/emotional problems and psychopathology, social anxiety and temperament in DEX-exposed school-aged children (n=26) and matched controls (n=35). In addition, the association between parental questionnaires and children's self-ratings was investigated.Results: There were no statistically significant differences between DEX-exposed children and controls in measures of psychopathology, behavioural problems and adaptive functioning. In a questionnaire on temperamental traits, DEX-exposed children were described by their parents as being more sociable than controls (P=0.042). The correlation analysis showed only modest parent–child agreement on social anxiety, i.e. the increased social anxiety in children's self-ratings was not confirmed by their parents.Conclusions: DEX-treated children showed good overall adjustment. The parent–child agreement with respect to social anxiety was modest, highlighting the importance of multiple information sources and assessment methods. The clinical significance of the observed difference in sociability cannot be determined within the frameworks of this study. Additional studies of larger cohorts are essential to make more decisive conclusions on the safety of the treatment. Until then, it is important that parents are thoroughly informed about the benefits and potential risks and uncertainties of this controversial treatment.

Congenital adrenal hyperplasia (CAH) refers to rare (∼1:10,000), recessively inherited disorders of adrenal steroidogenesis. 21-Hydroxylase deficiency, the most

Dexamethasone (DEX) is used to prevent virilization in female fetuses at risk of congenital adrenal hyperplasia (CAH). Given that treatment has to be started before the genotype is known, 7 out of 8 fetuses will be exposed to DEX without benefit. To evaluate long-term cognitive effects of prenatal DEX therapy in healthy (non-CAH) DEX-treated children. Observational study with patient and control groups from a single research institute. Healthy (non-CAH) DEX-treated subjects (n = 34) and untreated population controls (n = 66) from Sweden, aged 7-17 years. DEX-treatment used in unborn children at risk of CAH, during first trimester of fetal life. Standardized neuropsychological tests and questionnaires were used. DEX treatment has widespread negative effects in girls. In Wechsler Intelligence Scales for Children-III scale subtests, we observed significant interactions between DEX and GENDER (coding, P = .044; block design, P = .013; vocabulary, P = .025) and a trend for the subtest digit span (P = .074). All interactions were driven by DEX effects in girls, but not boys, with DEX-treated females showing lower scores than female untreated controls (coding, P = .068, d = 0.66; block design, P = .021, d = 0.81; vocabulary, P = .014, d = 0.84; digit span, P = .001, d = 1.0). Likewise, DEX-treated girls tend to have poorer visual spatial working memory performance than controls (span board test forward: P = .065, d = .80). We observed no effects on long-term memory, handedness, speed of processing, nor self-perceived or parentally reported scholastic performance. Early prenatal DEX exposure affects cognitive functions in healthy girls, ie, children who do not benefit from the treatment. It can therefore not be considered safe to use this therapy in the context of CAH.