Ribosomes translating damaged mRNAs may stall and prematurely split into their large and small subunits. The split large ribosome subunits can continue elongating stalled polypeptides. In yeast, this mRNA-independent translation appends the C-terminal alanine/threonine tail (CAT tail) to stalled polypeptides.
View Article and Find Full Text PDFIn mammals, the subgranular zone of the dentate gyrus is one of two brain regions (with the subventricular zone of the olfactory bulb) that continues to generate new neurons throughout adulthood, a phenomenon known as adult hippocampal neurogenesis (AHN) (Eriksson et al., Nat Med 4:1313-1317, 1998; García-Verdugo et al., J Neurobiol 36:234-248, 1998).
View Article and Find Full Text PDFTherapeutic use of electroconvulsive shock (ECS) is 75% effective for the remission of treatment-resistant depression. Like other more common forms of antidepressant treatment such as fluoxetine, ECS has been shown to increase neurogenesis in the hippocampal dentate gyrus of rodent models. Yet the question of how ECS-induced neurogenesis supports improvement of depressive symptoms remains unknown.
View Article and Find Full Text PDFBackground: Impairments in behavioral pattern separation (BPS)-the ability to distinguish between similar contexts or experiences-contribute to memory interference and overgeneralization seen in many neuropsychiatric conditions, including depression, anxiety, PTSD, dementia, and age-related cognitive decline. While BPS relies on the dentate gyrus and is sensitive to changes in adult hippocampal neurogenesis (AHN), its significance as a pharmacological target has not been tested.
Methods: In this study, we applied a human neural stem cell high-throughput screening cascade to identify compounds that increase human neurogenesis.
The etiologies of newborn deaths in neonatal intensive care units usually remain unknown, even after genetic testing. Whole-genome sequencing, combined with artificial intelligence-based methods for predicting the effects of non-coding variants, provide an avenue for resolving these deaths. Using one such method, SpliceAI, we identified a maternally inherited deep intronic PKHD1 splice variant (chr6:52030169T>C), in trans with a pathogenic missense variant (p.
View Article and Find Full Text PDFBackground: Previously, we recorded periods of time with foot higher than abdominal temperatures in association with infection in preterm infants. Monitoring dual temperatures may be an important tool to assess infant instability. Currently, incubators cannot measure and display dual temperatures in servo-control mode.
View Article and Find Full Text PDFBackground: Neonatal sepsis causes morbidity and mortality in preterm infants. Clinicians need a predictive tool for the onset of neonatal infection to expedite treatment and prevent morbidity. Abnormal thermal gradients, a central-peripheral temperature difference (CPtd) of >2°C or <0°C, and elevated heart rate characteristic (HRC) scores are associated with infection.
View Article and Find Full Text PDFG-rich DNA sequences with tracts of three or more continuous guanines (G≥3) are known to have high propensity to adopt stable G-quadruplex (G4) structures. Bioinformatic analyses suggest high prevalence of G-rich sequences with short G-tracts (G≤2) in the human genome. However, due to limited structural studies, the folding principles of such sequences remain largely unexplored and hence poorly understood.
View Article and Find Full Text PDFIn recent years, the regulation of brain networks and interactions between different brain regions have become important issues in neuroscience. Effective connectivity can be employed to understand the modulatory mechanisms of brain networks. Previous studies have used the task-positive mode to examine effective connectivity between brain regions and very few studies have considered the task-negative mode to explore effective connectivity using electroencephalography (EEG).
View Article and Find Full Text PDFBackground: Patients with schizophrenia (SZ) have impairments in processing auditory information that have been linked to deficits in cognitive and psychosocial functioning. Dysfunction in auditory sensory processing in SZ has been indexed by mismatch negativity (MMN), an event-related potential evoked by a rare, deviant stimulus embedded within a sequence of identical standard stimuli. Although MMN deficits in SZ have been studied extensively, relatively little is known about how these deficits relate to accurately identifying real-world, ecologically-salient sounds.
View Article and Find Full Text PDFBackgroud: Emotional dysregulation (EDR) is commonly seen in individuals with attention deficit hyperactive disorder (ADHD). But few are known about the influence of EDR on early-adulthood outcomes.
Aims: To detect the relationship between emotional dysregulation (EDR) in childhood and the outcomes in early-adulthood of participants with attention deficit hyperactive disorder (ADHD).
It is known that childhood attention-deficit/hyperactivity disorder (ADHD) persists into adulthood. Previous studies have demonstrated that gender, ADHD symptoms, functional impairment severity, medication treatment, IQ, comorbid with oppositional defiant disorder, conduct disorder and follow-up periods were associated with ADHD persistence in longitudinal samples of western population. In this study, we attempted to widely investigate the predictors particularly in a Chinese Han ADHD cohort.
View Article and Find Full Text PDFThe dopamine D4 receptor (DRD4) gene has been frequently studied in relation to attention deficit hyperactivity disorder (ADHD) but little is known about the contribution of single nucleotide polymorphisms (SNPs) of the DRD4 gene to the development and persistence of ADHD. In the present study, we examined the association between two SNPs in DRD4 (rs1800955, rs916455) and adult ADHD persistence in a Chinese sample. Subjects (n=193) were diagnosed with ADHD in childhood and reassessed in young adulthood at an affiliated clinic of Peking University Sixth Hospital.
View Article and Find Full Text PDFBackground: In rats, prepulse inhibition (PPI) of acoustic startle is disrupted by systemic administration of dopaminergic agonists, such as the dopamine D3 receptor (D3R)-preferential agonist pramipexole (PPX). PPX has D3R-active (S) and -inactive (R) stereoisomers. Here, we tested the neuroanatomical and stereochemical selectivity of PPX effects on PPI.
View Article and Find Full Text PDFPharmacol Biochem Behav
October 2011
Prepulse inhibition (PPI) of acoustic startle and locomotor activity are both widely studied in the preclinical development of dopaminergic agents, including those acting at D3 dopamine receptors. In mice, the dopamine D3 receptor-preferential agonist pramipexole (PPX) alters locomotor activity in a biphasic manner at doses that have no effect on PPI. The present study examined the time-course of PPX effects on locomotion and PPI in rats.
View Article and Find Full Text PDFThe preferential dopamine D3 receptor agonist pramipexole (PRA) disrupts prepulse inhibition (PPI) of acoustic startle, an operational measure of sensorimotor gating, in rats. Drug effects on PPI are sensitive to numerous experimental variables; proceeding with in-depth analyses of drug effects without a clear understanding of these variables is inefficient. The present studies characterized the impact on PRA-induced PPI deficits by a range of experimental parameters.
View Article and Find Full Text PDFEur Neuropsychopharmacol
June 2010
Dopamine agonists reduce prepulse inhibition (PPI) of startle in rats. While it is used to predict antipsychotic efficacy, the specific receptor subtypes mediating this effect of dopamine agonists remain unclear. We characterized the effects of sumanirole, a highly selective D2 agonist, on PPI in rats.
View Article and Find Full Text PDFPramipexole (PRA) is a preferential D3R agonist that, in rats and humans, modifies prepulse inhibition (PPI) of the acoustic startle reflex, an operational measure of sensorimotor gating. The ability to use similar PPI measures across species, and the relative ease of genetic manipulations in mice, suggests that molecular studies of the D3R regulation of sensorimotor gating might be best pursued in mice. Here, we evaluate the effects of PRA on PPI and locomotion in C57BL/6J mice, the background strain for many gene knockout mouse models.
View Article and Find Full Text PDFPsychopharmacology (Berl)
September 2009
Background: Dopamine D3 receptors regulate sensorimotor gating in rats, as evidenced by changes in prepulse inhibition (PPI) of startle after acute administration of D3 agonists and antagonists. In this study, we tested the effects of the D3-preferential agonist, pramipexole, on PPI in normal men and Sprague-Dawley rats.
Materials And Methods: Acoustic startle and PPI were tested in clinically normal men, comparing the effects of placebo vs.
Prepulse inhibition of startle (PPI) is an operational measure of sensorimotor gating that is impaired in schizophrenia. Treatment with mixed dopamine D2/D3 antagonists diminishes schizophrenia symptoms, and opposes dopamine agonist-induced PPI deficits in rats. There are reasons to believe that functional D3 receptor antagonists might offer more favorable therapeutic profiles compared to current antipsychotics.
View Article and Find Full Text PDFWe examined genome-wide expression datasets from human prefrontal cortex of normal and schizophrenic individuals ranging from 19 to 81 years of age. We found that changes in gene expression that are correlated with aging in normal subjects differ dramatically from those observed with aging in schizophrenic subjects. Only 2.
View Article and Find Full Text PDFPrepulse inhibition (PPI) of the startle reflex is an operational measure of sensorimotor gating that is deficient in several brain disorders and is disrupted in rats by dopamine (DA) agonists. Robust heritable strain differences are observed between Sprague-Dawley (SD) and Long-Evans (LE) strains in sensitivity to the PPI-disruptive effects of DA agonists associated with differential gene expression in the nucleus accumbens. Here, we compared the contribution of D2 versus D3 receptors with this heritable difference, using the D3-preferential agonist (pramipexole), the mixed D3/D2 agonist (quinpirole), the mixed D1/D2-like agonist (apomorphine), and the preferential D2 antagonist (L741,626).
View Article and Find Full Text PDFLittle is known about genetic regulation of the development of white matter. This knowledge is critical in understanding the pathophysiology of neurodevelopmental syndromes associated with altered cognition as well as in elucidating the genetics of normal human cognition. The hemideletion of approximately 25 genes on chromosome 7q11.
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