Fragile X mental retardation protein levels increase following complex environment exposure in rat brain regions undergoing active synaptogenesis

Fragile X mental retardation protein (FMRP), which is absent in fragile X syndrome, is synthesized in vitro in response to neurotransmitter activation. Humans and mice lacking FMRP exhibit abnormal dendritic spine development, suggesting that this protein plays an important role in synaptic plasticity. Previously, our laboratory demonstrated increased FMRP immunoreactivity in visual cortex of rats exposed to complex environments (EC) and in motor cortex of rats trained on motor-skill tasks compared with animals reared individually in standard laboratory housing (IC). Here, we use immunohistochemistry to extend those findings by investigating FMRP levels in visual cortex and hippocampal dentate gyrus of animals exposed to EC or IC. Rats exposed to EC for 20 days exhibited increased FMRP immunoreactivity in visual cortex compared with animals housed in standard laboratory caging. In the dentate gyrus, animals exposed to EC for 20 days had higher FMRP levels than animals exposed to EC for 5 or 10 days. In light of possible antibody crossreactivity with closely related proteins FXR1P and FXR2P, FMRP immunoreactivity in the posterior-dorsal one-third of cerebral cortex was also examined by Western blotting following 20 days of EC exposure. FMRP levels were greater in EC animals, whereas levels of FXR1P and FXR2P were unaffected by experience. These results provide further evidence for behaviorally induced alteration of FMRP expression in contrast to its homologues, extend previous findings suggesting regulation of its expression by synaptic activity, and support the theories associating FMRP expression with alteration of synaptic structure both in development and later in the life-cycle.     

Toddler autism screening questionnaire: development and potential clinical validity

No feasible screening instrument is available for early detection of children with autism in Taiwan. The existing instruments may not be appropriate for use in Taiwan due to different health care systems and child-rearing cultures. The purpose of this study was to develop and test a screening questionnaire for generic autism. The initial 18-item screening questionnaire was developed by a child psychiatrist using face-to-face interviews with 10 families of children with autism and then tested on a sample of families of 18 children with autism and of 59 typically developing children. Of these 18 items, 15 had fair or better item discrimination (kappa >0.20) and were selected for the revised screening questionnaire. In the revised questionnaire, cutoff scores of 5 and 6 offered 100% sensitivity and 96.5% specificity, with the area under the receiver operating characteristic curve of 0.983. The revised screening instrument has high sensitivity and specificity, making it potentially useful for screening Taiwanese children at risk for autism. This instrument should be further tested in a population-based study.     

Emotional/Behavioral Problems and Functional Impairment in Clinic- and Community-Based Children with Attention-Deficit/Hyperactivity Disorder in Taiwan

Using a sample of 268 patients and 137 community-based children with DSM-IV ADHD, and 268 school controls, aged 6–15, this study aimed to compare the emotional/behavioral problems and functional impairment between clinic- and community-based children with ADHD. Children’s ADHD-related symptoms, a wide range of emotional/behavioral problems, and functional impairments were assessed by the psychiatric interviews and self-, parent- and teacher-reported questionnaires. Both ADHD groups scored higher in parent- and teacher-reported ADHD-related symptoms, wide-ranging emotional/behavioral problems, and impairments in the school, peer, family, and leisure time domains than school controls. However, clinic-based children with ADHD had more physical/developmental problems, more severe functional impairments and teacher-reported hyperactivity/impulsivity symptoms, and higher family burdens than their community counterparts. Our findings suggest that a higher maternal educational level, parent’s perceived child functional impairment, teacher’s perceived impaired peer relationship and hyperactivity-impulsivity, and child physical and developmental problems may be related to the psychiatric referrals of children with ADHD.     

Dopamine induces LTP differentially in apical and basal dendrites through BDNF and voltage-dependent calcium channels

The dopaminergic modulation of long-term potentiation (LTP) has been studied well, but the mechanism by which dopamine induces LTP (DA-LTP) in CA1 pyramidal neurons is unknown. Here, we report that DA-LTP in basal dendrites is dependent while in apical dendrites it is independent of activation of L-type voltage-gated calcium channels (VDCC). Activation via NMDAR is critical for the induction of DA-LTP in both apical and basal dendrites, but only BDNF is required for the induction and maintenance of DA-LTP in apical dendrites. We report that dopaminergic modulation of LTP is lamina-specific at the Schaffer collateral/commissural synapses in the CA1 region.     

Internet-delivered assessment and manipulation of anxiety-linked attentional bias: Validation of a free-access attentional probe software package

It recently has been established within the laboratory that the attentional probe methodology not only can sensitively assess the threat attentional bias associated with anxiety vulnerability, but also can be configured to yield training tasks capable of modifying emotional vulnerability by manipulating such attentional selectivity. In order to appraise and exploit the potential practical applications of such procedures, it is desirable that clinical investigators without specialist equipment should become able to deliver such tasks within field settings. The present research program involved development of a fully customizable attentional probe software package, that delivers assessment and training versions of the probe task across the Internet. Two experimental studies served to validate the assessment and training efficacy of resulting probe task variants, completed remotely by GAD sufferers and nonclinical populations using their own computers. We advise fellow researchers how to freely download this software package for use within their own investigations.