Development of a novel rodent rapid serial visual presentation task reveals dissociable effects of stimulant versus nonstimulant treatments on attentional processes

The rapid serial visual presentation (RSVP) task and continuous performance tasks (CPT) are used to assess attentional impairments in patients with psychiatric and neurological conditions. This study developed a novel touchscreen task for rats based on the structure of a human RSVP task and used pharmacological manipulations to investigate their effects on different performance measures. Normal animals were trained to respond to a target image and withhold responding to distractor images presented within a continuous sequence. In a second version of the task, a false-alarm image was included, so performance could be assessed relative to two types of nontarget distractors. The effects of acute administration of stimulant and nonstimulant treatments for ADHD (amphetamine and atomoxetine) were tested in both tasks. Methylphenidate, ketamine, and nicotine were tested in the first task only. Amphetamine made animals more impulsive and decreased overall accuracy but increased accuracy when the target was presented early in the image sequence. Atomoxetine improved accuracy overall with a specific reduction in false-alarm responses and a shift in the attentional curve reflecting improved accuracy for targets later in the image sequence. However, atomoxetine also slowed responding and increased omissions. Ketamine, nicotine, and methylphenidate had no specific effects at the doses tested. These results suggest that stimulant versus nonstimulant treatments have different effects on attention and impulsive behaviour in this rat version of an RSVP task. These results also suggest that RSVP-like tasks have the potential to be used to study attention in rodents.

Affective biases and their interaction with other reward-related deficits in rodent models of psychiatric disorders

Major depressive disorder (MDD) is one of the leading global causes of disability. Symptoms of MDD can vary person to person, and current treatments often fail to alleviate the poor quality of life that patients experience. One of the two core diagnostic criteria for MDD is the loss of interest in previously pleasurable activities, which suggests a link between the disease aetiology and reward processing. Cognitive impairments are also common in patients with MDD, and more recently, emotional processing deficits known as affective biases have been recognised as a key feature of the disorder. Studies in animals have found similar affective biases related to reward. In this review we consider these affective biases in the context of other reward-related deficits and examine how affective biases associated with learning and memory may interact with the wider behavioural symptoms seen in MDD. We discuss recent developments in how analogues of affective biases and other aspects of reward processing can be assessed in rodents, as well as how these behaviours are influenced in models of MDD. We subsequently discuss evidence for the neurobiological mechanisms contributing to one or more reward-related deficits in preclinical models of MDD, identified using these behavioural assays. We consider how the relationships between these selective behavioural assays and the neurobiological mechanisms for affective bias and reward processing could be used to identify potential treatment strategies.

P727Metabolic and functional differences between male and female endothelial cells from umbilical cords (HUVEC) of twin pairs

Background

Personalised Medicine is one of the hallmarks of future medicine. Sex and gender differences exist in the incidence, clinical manifestation and outcome of cardiovascular diseases. Gonadal hormones are thought to account for most of these sex differences. However, besides hormones, sexual dimorphisms at the cellular level may also contribute to physiological and pathophysiological cardiovascular differences between women and men.

Purpose

To analyse intrinsic sex differences at the cellular level, we aimed to elucidate sex-specific differences in endothelial cell migration and energy metabolism under pro-migratory conditions in male and female HUVECs. To reduce biological variability, we used HUVECS obtained from umbilical cords from twin pairs of the opposite sex. These cells are exposed in utero to the same maternal environment, and therefore represent a valuable tool to study intrinsic sex-specific differences at the cellular level.

Methods

Vascular endothelial growth factor (VEGF)-stimulated migration was determined with IBIDI migration chambers. Sex-specific levels of proteins were studied using proteome profiling. Cellular metabolism was measured by Seahorse and levels of intracellular metabolites were analysed using GC-MS based technology.

Results

Female cells showed significantly higher VEGF-induced cell migration than male HUVECs. Proteomic profiling revealed a sex-specific response to VEGF treatment. Mitochondrial respiration rate was higher in VEGF-stimulated male HUVECs compared to female cells. Whereas mean glycolytic rates did not significantly differ between sexes, the ratio of glycolysis/mitochondrial respiration after VEGF stimulation was higher in female than in male HUVECs. Female cells had higher intracellular ATP levels after serum starvation and treatment with VEGF. Under both conditions, female cells showed altered levels of metabolite pools compared to male HUVECs.

Conclusions

Higher intracellular ATP and metabolite levels in female cells after serum starvation and VEGF may contribute to the observed functional sexual dimorphisms, and may also point to an increased stress tolerance of female cells. The results of our study provide a strong argument to discriminate between male and female cells in in vitro experiments.

Acknowledgement/Funding

The work was supported by the DZHK (German Centre for Cardiovascular Research) and by the BMBF (German Ministry of Education and Research).

Differential roles for cortical versus sub-cortical noradrenaline and modulation of impulsivity in the rat

RATIONALE

Atomoxetine is a noradrenaline re-uptake inhibitor licensed for the treatment of adult and childhood attention deficit hyperactivity disorder. Although atomoxetine has established efficacy, the mechanisms which mediate its effects are not well understood.

OBJECTIVES

In this study, we investigated the role of cortical versus sub-cortical noradrenaline by using focal dopamine beta hydroxylase-saporin-induced lesions, to the prefrontal cortex (n = 16) or nucleus accumbens shell (n = 18).

METHODS

Healthy animals were tested by using the forced-choice serial reaction time task to assess the impact of the lesion on baseline performance and the response to atomoxetine and the psychostimulant amphetamine.

RESULTS

We observed attenuation in the efficacy of atomoxetine in animals with lesions to the nucleus accumbens shell, but not the prefrontal cortex. Amphetamine-induced increases in premature responses were potentiated in animals with lesions to the prefrontal cortex, but not the nucleus accumbens shell.

CONCLUSIONS

These data suggest that noradrenaline in the nucleus accumbens shell plays an important role in the effects of atomoxetine. Under these conditions, prefrontal cortex noradrenaline did not appear to contribute to atomoxetine's effects suggesting a lack of cortical-mediated "top-down" modulation. Noradrenaline in the prefrontal cortex appears to contribute to the modulation of impulsive responding in amphetamine-treated animals, with a loss of noradrenaline associated with potentiation of its effects. These data demonstrate a potential dissociation between cortical and sub-cortical noradrenergic mechanisms and impulse control in terms of the actions of atomoxetine and amphetamine.

Defects in glycosylation impair satellite stem cell function and niche composition in the muscles of the dystrophic Large(myd) mouse

The dystrophin-associated glycoprotein complex (DGC) is found at the muscle fiber sarcolemma and forms an essential structural link between the basal lamina and internal cytoskeleton. In a set of muscular dystrophies known as the dystroglycanopathies, hypoglycosylation of the DGC component α-dystroglycan results in reduced binding to basal lamina components, a loss in structural stability, and repeated cycles of muscle fiber degeneration and regeneration. The satellite cells are the key stem cells responsible for muscle repair and reside between the basal lamina and sarcolemma. In this study, we aimed to determine whether pathological changes associated with the dystroglycanopathies affect satellite cell function. In the Large(myd) mouse dystroglycanopathy model, satellite cells are present in significantly greater numbers but display reduced proliferation on their native muscle fibers in vitro, compared with wild type. However, when removed from their fiber, proliferation in culture is restored to that of wild type. Immunohistochemical analysis of Large(myd) muscle reveals alterations to the basal lamina and interstitium, including marked disorganization of laminin, upregulation of fibronectin and collagens. Proliferation and differentiation of wild-type satellite cells is impaired when cultured on substrates such as collagen and fibronectin, compared with laminins. When engrafted into irradiated tibialis anterior muscles of mdx-nude mice, wild-type satellite cells expanded on laminin contribute significantly more to muscle regeneration than those expanded on fibronectin. These results suggest that defects in α-dystroglycan glycosylation are associated with an alteration in the satellite cell niche, and that regenerative potential in the dystroglycanopathies may be perturbed.

Randomised controlled trial of cognitive-behavioural therapy in early schizophrenia: acute-phase outcomes

BACKGROUND

Cognitive-behavioural therapy (CBT) improves persistent psychotic symptoms.

AIMS

To test the effectiveness of added CBT in accelerating remission from acute psychotic symptoms in early schizophrenia.

METHOD

A 5-week CBT programme plus routine care was compared with supportive counselling plus routine care and routine care alone in a multi-centre trial randomising 315 people with DSM-IV schizophrenia and related disorders in their first (83%) or second acute admission. Outcome assessments were blinded.

RESULTS

Linear regression over 70 days showed predicted trends towards faster improvement in the CBT group. Uncorrected univariate comparisons showed significant benefits at 4 but not 6 weeks for CBT v. routine care alone on Positive and Negative Syndrome Scale total and positive sub-scale scores and delusion score and benefits v. supportive counselling for auditory hallucinations score.

CONCLUSIONS

CBT shows transient advantages over routine care alone or supportive counselling in speeding remission from acute symptoms in early schizophrenia.

Dentigerous cysts of inflammatory origin. A clinicopathologic study

The exact histogenesis of dentigerous cysts remains unknown, but most authors favor a developmental origin from the tooth follicle. The aim of this article is to report a series of 15 dentigerous cysts that we believe to be of inflammatory origin. These inflammatory dentigerous cysts occurred in the first and early part of the second decades of life. Males were affected more frequently, and there did not appear to be any racial predilection. All of the cases involved permanent teeth: premolars in nine cases, canines in four cases, and second molars in two cases. The mandible was affected twice as frequently as the maxilla. In 13 cases, nonvital grossly carious or heavily restored deciduous teeth were associated with the cysts. Some of these teeth had been extracted before the cysts were diagnosed. In the remaining two cases, both of which involved the second permanent molars, there were no nonvital deciduous teeth, however both had concomitant proliferative periostitis. All of the cysts were moderately or intensely inflamed and were lined predominantly or entirely by nonkeratinized stratified squamous epithelium that in some cases was markedly hyperplastic and exhibited anastomosing rete ridges mimicking radicular cysts. In the majority of cases, parts of the cysts were lined with a 2 to 3 cell layer thick cuboidal epithelium that we believe was derived from reduced enamel epithelium. Rests of odontogenic epithelium frequently were evident in the cyst walls. We suggest that these cysts arose as a result of periapical inflammation from any source but usually from a nonvital deciduous tooth and spreading to involve the follicles of the unerupted permanent successors. The inflammatory exudate causes separation of the reduced enamel epithelium from the enamel with resultant cyst formation. This study proposes the existence of two types of dentigerous cysts: one developmental and the other inflammatory in nature.

ST segment alternans during coronary angioplasty

Four patients with severe proximal or mid-LAD stenosis were noted to have ST alternans during balloon angioplasty. Neither mechanical alternans nor increased ventricular ectopy were noted. In contrast to prior descriptions in animals or patients with variant angina, ST alternans did not occur following a premature ventricular contraction. Frequent use of calcium channel blockers during PTCA may interfere with the mechanism leading to electrical alternans and its consequences as seen in animal studies, accounting for the low frequency with which this phenomenon is noted during PTCA.

The technique of inserting an intra-aortic balloon pump. Indications, contraindications, advice for avoiding complications

The intra-aortic balloon pump (IABP) uses the timed inflation and deflation of a balloon placed in the descending aorta to augment coronary perfusion and reduce myocardial work. The IABP is useful in a number of settings, including acute myocardial ischemia, cardiogenic shock, and mechanical complications of acute myocardial infarction; it also provides support to perioperative patients. Because the device can be inserted percutaneously, mechanical circulatory support can be instituted rapidly Complications, most of which are reversible, occur in approximately 30% of patients.

Primary structure and expression of a chicken cDNA encoding a protein with zinc-finger motifs

We report the cloning and sequence analysis of a chicken nearly full-length cDNA clone, cKr1, encoding a protein of 509 amino acids which contains ten 2Cys + 2His-type zinc-finger motifs arranged in two separate sets of five zinc fingers each. The cKr1 transcripts are detected in organs of the adult chicken, predominantly in the brain and lung. At day 4 of embryonic development strong cKr1 hybridization signals are found in the brain and neural tube, in the mesonephros and in the gut, respectively.

Clinical correlates do not predict PaO2 response after tolazoline administration in hypoxic newborns

In an attempt to determine which hypoxic newborns might benefit from administration of tolazoline hydrochloride (Tz), we identified all neonates known to have received Tz at four Chicago area perinatal centers over a 4-yr period. For each of 41 infants, five statistical analyses were used to correlate 31 clinical and ventilatory variables with PaO2 values before and after Tz administration. Fourteen neonates responded to Tz infusion with more than a two-fold increase in PaO2. None of 31 clinical variables successfully predicted a positive Tz response in these infants, and a positive response (increased PaO2) was not associated with increased likelihood of survival. BP fell after Tz in 72% of patients, while heart rate rose after Tz treatment in 66% of cases. These data suggest a need to re-evaluate the administration of Tz to hypoxic newborn infants.

A fetus with a chromosome 13 ring and placenta with chromosome 13 rod/ring mosaicism

A fetus was identified by prenatal cytogenetic diagnosis as having a karyotype 46,XY,r(13) (p11q13). Termination of the pregnancy yielded a severely malformed fetus. Fetal abnormalities included anencephaly, imperforate anus and urethral meatus, severe talipes, syndactyly, cardiac defects and other anomalies. Confirmatory studies on cultured placental villi cells indicated a second cell line, 46,XY, -13,+13qter leads to cen::13q13 leads to qter. This cell line was not detectable in cells derived from the fetus despite extensive studies. It seems likely that the two cell lines arose simultaneously with selection favouring the 46,XY,r(13) line. How the chromosome rearrangements may have arisen is discussed. We are unaware of other cases where a cell line identifiable by a chromosome abnormality appeared to be confined to placental tissue. However, studies on placental tissue may be helpful in understanding the origin of other unbalanced de novo rearrangements.

Effect of intraluminal pH on the absorption of pteroylmonoglutamic acid

The administration of pteroylmonoglutamic acid and either sodium bicarbonate or phenytoin sodium in normal subjects and epileptics results in lower serum levels of folic acid than when administered alone. Bicarbonate administration was shown to produce a more alkaline pH in the jejunum, while an alkaline pH was found in some epileptics on phenytoin therapy. The physicochemical mechanisms whereby folic acid absorption is reduced in an alkaline medium are considered, and the implications on folate absorption in other disease states are discussed. The mechanism by which phenytoin sodium alters the intrajejunal milieu is obscure.

Maximal acid output and oesophagitis in hiatus hernia

It has been suggested (Casten, Bernhang, Nach, and Spinzia, 1963) that patients with symptomatic sliding hiatus hernia have a higher acid output than the normal patient, but this has recently been disputed by Williams, Lawrie, and Forrest (1967). These latter workers found that there is no significant increase in maximal acid output in patients with sliding hiatus hernia. Aylwin (1953) demonstrated a correlation between the degree of oesophagitis in sliding hiatus hernia and the enzyme activity of juices bathing the oesophagus at night, and suggested that this was the chief factor in the production of oesophagitis. In this study patients with hiatus hernia were investigated to see if there was any correlation between the degree of oesophagitis and the maximal acid output. The maximal acid output in patients with hiatus hernia was found not to differ significantly from normal, and the degree of oesophagitis in the patients with oesophageal reflux was not closely related to the maximal acid output.