Search

The "cognitive styles" hypothesis suggests that individual differences in behavior are associated with variation in cognitive performance via underlying speed-accuracy trade-offs. While this is supported, in part, by a growing body of evidence, some studies did not find the expected relationships between behavioral type and cognitive performance. In some cases, this may reflect methodological limitations rather than the absence of a true relationship. The physical design of the testing arena and the number of choices offered in an assay can hinder our ability to detect inter-individual differences in cognitive performance. Here, we re-investigated the cognitive styles hypothesis in threespine stickleback ( Gasterosteus aculeatus ), adapting the maze design of a previous study which found no cost to decision success by faster (bolder) individuals. We used a similar design but increased the size of the maze and incorporated an additional choice in the form of a third maze arm. We found, in accordance with cognitive style expectations, that individuals who were consistently slower to emerge from the start chamber made fewer errors than fish that emerged faster. Activity in an open field test, however, did not show evidence of a relationship with decision success, possibly due to the low number of repeated observations per fish in this separate assay. Our results provide further empirical support for the cognitive styles hypothesis and highlight important methodological aspects to consider in studies of inter-individual differences in cognition., (© The Author(s) 2024. Published by Oxford University Press on behalf of the International Society for Behavioral Ecology.)

Current climate change models predict an increase in temperature variability and extreme events such as heatwaves, and organisms need to cope with consequent changes to environmental variation. Non-genetic inheritance mechanisms can enable parental generations to prime their offspring's abilities to acclimate to environmental change-but they may also be deleterious. When parents are exposed to predictable environments, intergenerational plasticity can lead to better offspring trait performance in matching environments. Alternatively, parents exposed to variable or unpredictable environments may use plastic bet-hedging strategies to adjust the phenotypic variance among offspring. Here, we used a model species, the threespine stickleback (Gasterosteus aculeatus), to test whether putatively adaptive intergenerational effects can occur in response to shifts in environmental variation as well as to shifts in environmental mean, and whether parents employ plastic bet-hedging strategies in response to increasing environmental variation. We used a full-factorial, split-clutch experiment with parents and offspring exposed to three temperature regimes: constant, natural variation, and increased variation. We show that within-generation exposure to increased temperature variation reduces growth of offspring, but having parents that were exposed to natural temperature variation during gametogenesis may offset some early-life negative growth effects. However, these mitigating intergenerational effects do not appear to persist later in life. We found no indication that stickleback mothers plastically altered offspring phenotypic variance (egg size or clutch size) in response to temperature variation. However, lower inter-individual variance of juvenile fish morphology in offspring of increased variation parents may imply the presence of conservative bet-hedging strategies in natural populations. Overall, in our experiment, parental exposure to temperature variation had limited effects on offspring fitness-related traits. Natural levels of environmental variation promoted a potentially adaptive intergenerational response in early life development, but under more challenging conditions associated with increased environmental variation, the effect was lost., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Spence-Jones et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Background: International longitudinal studies have indicated an increasing incidence of diabetic ketoacidosis (DKA). We aim to examine the incident trends, demographic differences, length of stay and mortality for DKA in adults with type 1 diabetes (T1D) and type 2 diabetes (T2D) in Victoria, Australia from 2002 to 2016., Methods: Age and sex adjusted incident trends, length of stay and mortality for DKA was retrospectively obtained using the Victorian Admitted Episode Dataset between 2002 and 2016. Data for adults with T1D and T2D was obtained from the National Diabetes Services Scheme (NDSS). Joinpoint regression analysis was used to identify changes in linear trends that were described as average annual percentage change (AAPC)., Results: There were 23,628 DKA presentations in Victoria between 2002 and 2016. For T1D there was an increase in DKA presentations (AAPC + 6.8%) from 2003 to 2016 and for T2D there was a decline from 2003 to 2011 (APC - 3.5%), increase from 2011 to 2014 (APC + 38.5%), and a decrease from 2014 to 2016 (APC - 20.9%). Length of stay was longer for people with T2D than T1D (P < 0.001) and the mortality rate was 0.51% for the study period., Conclusions: DKA rates increased for T2D from 2011 to 2014 which correlates with the introduction of sodium glucose-linked transport protein 2 inhibitors. However, the aetiology for the observed increase in T1D from 2002 to 2016 remains unknown., (© 2024. The Author(s).)

Although studies on fish cognition are increasing, consideration of how methodological details influence the ability to detect and measure performance is lagging. Here, in two separate experiments the authors compared latency to leave the start position, latency to make a decision, levels of participation and success rates (whether fish entered the rewarded chamber as first choice) across different physical designs. Experiments compared fish performance across (a) two sizes of T-mazes, large and standard, and a plus-maze, and (b) open choice arenas with either two or four doors. Fish in T-mazes with longer arms took longer to leave the start chamber and were less likely to participate in a trial than fish in T-mazes with shorter arms. The number of options, or complexity, in a maze significantly impacted success but did not necessarily impact behavioural measures, and did not impact the number of fish that reached a chamber. Fish in the plus-maze had similar latencies to leave the start box and time to reach any chamber as fish in the same-sized T-maze but exhibited lower overall success. Similarly, in an open choice arena, increasing the number of options - doors to potential reward chambers - resulted in lower probability of success. There was an influence of reward position in the choice arena, with rewarded chambers closest to the sides of the arena resulting in lower latencies to enter and higher probability of decision success. Together the results allow the authors to offer practical suggestions towards optimal maze design for studies of fish cognition., (© 2023 The Authors. Journal of Fish Biology published by John Wiley & Sons Ltd on behalf of Fisheries Society of the British Isles.)

During aging, proteostasis capacity declines and distinct proteins become unstable and can accumulate as protein aggregates inside and outside of cells. Both in disease and during aging, proteins selectively aggregate in certain tissues and not others. Yet, tissue-specific regulation of cytoplasmic protein aggregation remains poorly understood. Surprisingly, we found that the inhibition of 3 core protein quality control systems, namely chaperones, the proteasome, and macroautophagy, leads to lower levels of age-dependent protein aggregation in Caenorhabditis elegans pharyngeal muscles, but higher levels in body-wall muscles. We describe a novel safety mechanism that selectively targets newly synthesized proteins to suppress their aggregation and associated proteotoxicity. The safety mechanism relies on macroautophagy-independent lysosomal degradation and involves several previously uncharacterized components of the intracellular pathogen response (IPR). We propose that this protective mechanism engages an anti-aggregation machinery targeting aggregating proteins for lysosomal degradation., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Jung et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

An archazolid natural product fragment that displays dose-dependent inhibition of the vacuolar-type ATPase (VATPase) has been synthesized by a high-yielding Suzuki coupling of two complex subunits. Similarly, a further simplified fragment was prepared and evaluated for VATPase inhibitory activity. This compound did inhibit the VATPase, as evidenced by growth inhibition of etiolated Arabidopsis seedlings, however at approximately 10× lower potency than the more complex fragment. Cyclooxygenase (COX) enzyme inhibition was not observed for either fragment., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

We compared preferences shown by zebrafish Danio rerio and three-spined stickleback Gasterosteus aculeatus for shelter provided by above-tank shade and artificial plants. Zebrafish showed no preference for either shelter, whereas sticklebacks showed a preference for both shelter types over open areas and for shade over plants. Our results suggest shade may be used as enrichment for captive fish and re-emphasise the importance of species-specific welfare considerations., (© 2019 The Fisheries Society of the British Isles.)

Background: Clinical research is increasing across the United Kingdom. Within the context of a shortage of nurses, trusts have struggled to maintain research capacity. In order to meet staffing demands, trusts have increasingly turned to Clinical Research Practitioners (CRPs) to assist in the delivery of clinical research. Initially an ad hoc workforce, the CRP role is being formalised and professionalised. This study is a close examination of the clinical research delivery workforce at one research-intensive acute trust in the United Kingdom, with a focus on the emerging CRP staff group., Methods: The study was conducted in a large inner-city teaching hospital (acute trust) in London, United Kingdom. Data were collected between September and December 2017. Twenty-five staff were interviewed across 11 different directorates. Interviews were semi-structured with an overall focus on research staff backgrounds and roles, as well as their perceptions and experiences of careers in research. The data were managed using NVivo 11 software and analysed thematically., Results: CRPs are drawn from a wider pool of educational and employment backgrounds than their nurse colleagues, and actively seek out work in health research. CRPs receive on-the-job training to acquire the competencies that are necessary for them to carry out their work. The CRP role, which began in an ad hoc manner, has become regularised, yet remains to be well defined, which can be a source of frustration for CRPs and those who work with them., Conclusions: The professionalisation of the CRP workforce represents an opportunity for the health research system to employ research workers who possess a range of in-demand skills and to shore up research capacity in the context of the shortage of nurses.

After publication of the article [1], it has been brought to our attention that there are some errors in the formatting of names in the final version of the article.

In cooperative breeders, aggression from dominant breeders directed at subordinates may raise subordinate stress hormone (glucocorticoid) concentrations. This may benefit dominants by suppressing subordinate reproduction but it is uncertain whether aggression from dominants can elevate subordinate cooperative behaviour, or how resulting changes in subordinate glucocorticoid concentrations affect their cooperative behaviour. We show here that the effects of manipulating glucocorticoid concentrations in wild meerkats ( Suricata suricatta ) on cooperative behaviour varied between cooperative activities as well as between the sexes. Subordinates of both sexes treated with a glucocorticoid receptor antagonist (mifepristone) exhibited significantly more pup protection behaviour (babysitting) compared to those treated with glucocorticoids (cortisol) or controls. Females treated with mifepristone had a higher probability of exhibiting pup food provisioning (pup-feeding) compared to those treated with cortisol. In males, there were no treatment effects on the probability of pup-feeding, but those treated with cortisol gave a higher proportion of the food they found to pups than those treated with mifepristone. Using 19 years of behavioural data, we also show that dominant females did not increase the frequency with which they directed aggression at subordinates at times when the need for assistance was highest. Our results suggest that it is unlikely that dominant females manipulate the cooperative behaviour of subordinates through the effects of aggression on their glucocorticoid levels and that the function of aggression directed at subordinates is probably to reduce the probability they will breed., (© 2017 The Author(s).)

In group-living mammals, the eviction of subordinate females from breeding groups by dominants may serve to reduce feeding competition or to reduce breeding competition. Here, we combined both correlational and experimental approaches to investigate whether increases in food intake by dominant females reduces their tendency to evict subordinate females in wild meerkats ( Suricata suricatta ). We used 20 years of long-term data to examine the association between foraging success and eviction rate, and provisioned dominant females during the second half of their pregnancy, when they most commonly evict subordinates. We show that rather than reducing the tendency for dominants to evict subordinates, foraging success of dominant females is positively associated with the probability that pregnant dominant females will evict subordinate females and that experimental feeding increased their rates of eviction. Our results suggest that it is unlikely that the eviction of subordinate females serves to reduce feeding competition and that its principal function may be to reduce reproductive competition. The increase in eviction rates following experimental feeding also suggests that rather than feeding competition, energetic constraints may normally constrain eviction rates., (© 2017 The Author(s).)

This article gives an overview of two research-related roles that can form part of a nurse's career path: clinical research nurse and nurse researcher. It highlights the influences on both roles, and the skills and differences within them, as well as offering advice on how nurses can access either role.

Background: Murine Zic genes (Zic1-5) are expressed in the dorsal hindbrain and in periotic mesenchyme (POM) adjacent to the developing inner ear. Zic genes are involved in developmental signaling pathways in many organ systems, including the ear, although their exact roles haven't been fully elucidated. This report examines the role of Zic1, Zic2, and Zic4 during inner ear development in mouse mutants in which these Zic genes are affected., Results: Zic1/Zic4 double mutants don't exhibit any apparent defects in inner ear morphology. By contrast, inner ears from Zic2(kd/kd) and Zic2(Ku/Ku) mutants have severe but variable morphological defects in endolymphatic duct/sac and semicircular canal formation and in cochlear extension in the inner ear. Analysis of otocyst patterning in the Zic2(Ku/Ku) mutants by in situ hybridization showed changes in the expression patterns of Gbx2 and Pax2., Conclusions: The experiments provide the first genetic evidence that the Zic genes are required for morphogenesis of the inner ear. Zic2 loss-of-function doesn't prevent initial otocyst patterning but leads to molecular abnormalities concomitant with morphogenesis of the endolymphatic duct. Functional hearing deficits often accompany inner ear dysmorphologies, making Zic2 a novel candidate gene for ongoing efforts to identify the genetic basis of human hearing loss., (© 2014 Wiley Periodicals, Inc.)

This editorial announces a new affiliation between Fluids and Barriers of the CNS (FBCNS) and the International Brain Barriers Society (IBBS) with mutual benefits to the journal and to society members. This is a natural progression from the appointment of two new Co-Editors in Chief: Professor Lester Drewes and Professor Richard Keep in 2013. FBCNS provides a unique and specialist platform for the publication of research in the expanding fields of brain barriers and brain fluid systems in both health and disease.

The first molecular herald of organ asymmetry during murine embryogenesis is found at the periphery of the node in early-somite stage embryos. Asymmetric gene expression and calcium accumulation at the node occurs in response to a left-ward flow of extracellular fluid across the node, generated by motile cilia within the pit of the node and likely sensed by immotile cilia in the periphery of the node. The ciliation of node cells is controlled by a cascade of node-restricted transcription factor activity during mid-late gastrulation. Mutation of the murine Zic2 transcription factor is associated with random cardiac situs and a loss of asymmetric gene expression at the early-somite node and in the lateral plate. Zic2 is not expressed in these regions but is transiently expressed in the mid-late gastrula node at the time of ciliogenesis. The cilia of the node are overtly abnormal in Zic2 mutant embryos being dysmorphic and short relative to wild-type littermates. The expression of the Noto, Rfx3, and Foxj1 transcription factors known to regulate ciliogenesis is greatly depleted in the mid-gastrula node of mutants, as is the expression of the Pkd1l1 gene required for cilia function. Zic2 appears to be a component of the gene regulatory network that drives ciliation of node cells during gastrulation., (© 2014 Wiley Periodicals, Inc.)

Since its development in the 1970's, whole embryo culture (WEC) has provided an important method of growing and observing murine embryos ex utero. During WEC, embryos are immersed in a combination of rat serum and cell culture media, and supplied with heat and appropriate mixtures of CO₂ and oxygen that mimic growth conditions in utero. One significant factor limiting the widespread use of WEC is the perception that commercially produced rat serum is inadequate to support normal rates of embryonic growth and development. Conversely, production of serum 'in-house' is technically demanding, time-consuming and expensive. The current study aimed to identify a WEC medium comprising commercially manufactured rat serum that would produce cultured embryos of comparable standard to those grown in utero. A mixed culture medium, composed of 50% commercial rat serum and 50% F12 Ham's cell culture medium with an N-2 neuronal cell growth supplement, was shown to support both a rate of growth, and the development of a range of features comparable to that which normally occur in vivo. Furthermore, the F12 (N-2) supplemented rat serum displayed a very low propensity to induce morphological abnormalities during the culture period. The study establishes a novel method of successful WEC using readily available commercial reagents and should enable the broader use of WEC.

Recent research on motivational intensity has shown that explicit manipulations of self-focused attention (e.g., mirrors and video cameras) increase effort-related cardiovascular responses during active coping. An experiment examined whether masked first name priming, an implicit manipulation of self-focused attention, had similar effects. Participants (n=52 young adults) performed a self-paced cognitive task, in which they were told to get as many trials correct as possible within 5min. During the task, the participant's first name was primed for 0%, 33%, 67%, or 100% of the trials. First name priming, regardless of its frequency, significantly increased cardiovascular reactivity, particularly systolic blood pressure (SBP) reactivity. Furthermore, the priming manipulation interacted with individual differences in trait self-focus: trait self-focus predicted higher SBP reactivity in the 0% condition, but first name priming eliminated the effects of individual differences. Implications for self-awareness research and for the emerging interest in priming effects on effort are considered., (2011 Elsevier B.V. All rights reserved.)

Using motivational intensity theory as a framework, the present experiment examined how individual differences in self-focused attention interact with task difficulty to predict effort, assessed via cardiovascular reactivity. Participants (n = 50) worked on a cognitive task fixed at an easy, medium, or hard level of difficulty, and individual differences in private self-consciousness and self-reflection were measured. Regression models indicated that trait self-focus interacted with task difficulty to predict cardiovascular reactivity, particularly systolic blood pressure (SBP) reactivity. Participants low and high in trait self-focus showed similar SBP reactivity in the easy and medium conditions, but they diverged in the hard condition: High trait focus was associated with higher SBP reactivity, indicating greater effort, whereas low trait self-focus was associated with low SBP reactivity, indicating disengagement. The findings thus support the motivational intensity approach to effort and its interpretation of self-focus's role in effort mobilization., (Copyright © 2010 Elsevier B.V. All rights reserved.)

This article celebrates the re-launch of Cerebrospinal Fluid Research in its new format as Fluids and Barriers of the CNS. Editors-in Chief, Hazel Jones and Tetsuya Terasaki, anticipate that this expanded journal will provide a unique and specialist platform for the publication of research in cerebrospinal fluid and all brain barriers and fluid systems in both health and disease.

Object: Despite the investigations that have linked hydrocephalus to reproductive system abnormalities, no researchers have attempted to identify the pathophysiological mechanism of this relationship. Because the role of the hypothalamic gonadotrophin-releasing hormone (GnRH) system in the regulation of reproductive functions is well established, the authors used immunohistochemical and radioimmunoassay (RIA) techniques to determine the morphological and biochemical effects of hydrocephalus on the hypothalamic GnRH system., Methods: Hypothalamic GnRH levels, fiber density, and cell types were studied in 21- and 50-day-old control and congenitally hydrocephalic Texas rats. Results of RIA indicated a significant (8.4%) increase in GnRH in 21-day-old hydrocephalic rats (9.17 +/- 0.64 pg/ng total protein) compared with that in controls (0.97 +/- 0.74 pg/ng total protein). In addition, the 50-day-old hydrocephalic animals had a significantly higher level of GnRH compared with age-matched controls (20.4 pg/ng compared with 1.88 +/- 2.1 pg/ng total protein). This increase was accompanied by changes in the fiber appearance and a shift from low GnRH producing cells to high GnRH producing cells in the hydrocephalic animals; however, there was no significant difference in the fiber density between the control and hydrocephalic animals at 21 days. In addition, poor neurological scores correlated with the severity of hydrocephalus., Conclusions: These results demonstrated that hypothalamic GnRH levels are significantly affected by fetal-onset hydrocephalus and that the mechanisms responsible for these effects may take place at the cellular rather than the gross structural level. Furthermore, they suggest that impairments in the GnRH system may be protracted in neonates and infants with hydrocephalus, and thus may be overcome by relatively early treatment with ventricular diversion. However, the clinical implications of GnRH perturbations in shunt-dependent patients must await a forthcoming study in shunted animals.

Article processing charges (APCs) have recently been introduced for authors submitting papers to Cerebrospinal Fluid Research. This editorial is to inform readers about the need and use of APCs and about the advantages of free open access publishing.

Background: The LEW/Jms rat strain has inherited hydrocephalus, with more males affected than females and an overall expression rate of 28%. This study aimed to determine chromosomal positions for genetic loci causing the hydrocephalus., Methods: An F1 backcross was made to the parental LEW/Jms strain from a cross with non-hydrocephalic Fischer 344 rats. BC1 rats were generated for two specific crosses: the first with a male LEW/Jms rat as parent and grandparent, [(F x L) x L], designated B group, and the second with a female LEW/Jms rat as the parent and grandparent [L x (L x F)], designated C group. All hydrocephalic and a similar number of non-hydrocephalic rats from these two groups were genotyped with microsatellite markers and the data was analyzed separately for each sex by MAPMAKER., Results: The frequency of hydrocephalus was not significantly different between the two groups (18.2 and 19.9 %), but there was a significant excess of males in the B group. The mean severity of hydrocephalus, measured as the ventricle-to-brain width ratio, was ranked as B group < C group < LEW/Jms. For the both rat groups, there were several chromosomes that showed possible regions with association between phenotype and genotype significant at the 5% or 1.0% level, but none of these had significant LOD scores. For the C group with a female LEW/Jms parent, there was a fully significant locus on Chr2 with a LOD score of 3.81 that was associated almost exclusively with male rats. Both groups showed possible linkage on Chr17 and the data combined produced a LOD score of 2.71, between suggestive and full significance. This locus was largely associated with male rats with a LEW/Jms male parent., Conclusion: Phenotypic expression of hydrocephalus in Lew/Jms, although not X-linked, has a strong male bias. One, and possibly two chromosomal regions are associated with the hydrocephalus.

The H-Tx rat has fetal-onset hydrocephalus with a complex mode of inheritance. Previously, quantitative trait locus mapping using a backcross with Fischer F344 rats demonstrated genetic loci significantly linked to hydrocephalus on Chromosomes 10, 11, and 17. Hydrocephalus was preferentially associated with heterozygous alleles on Chrs 10 and 11 and with homozygous alleles on Chr 17. This study aimed to determine the phenotypic contribution of each locus by constructing single and multiple congenic strains. Single congenic rats were constructed using Fischer F344 as the recipient strain and a marker-assisted protocol. The homozygous strains were maintained for eight generations and the brains examined for dilated ventricles indicative for hydrocephalus. No congenic rats had severe (overt) hydrocephalus. A few pups and a significant number of adults had mild disease. The incidence was significantly higher in the C10 and C17 congenic strains than in the nonhydrocephalic F344 strain. Breeding to F344 to make F.H-Tx C10 or C11 rats heterozygous for the hydrocephalus locus failed to produce progeny with severe disease. Both bicongenic and tricongenic rats of different genotype combinations were constructed by crossing congenic rats. None had severe disease but the frequency of mild hydrocephalus in adults was similar to congenic rats and significantly higher than in the F344 strain. Rats with severe hydrocephalus were recovered in low numbers when single congenic or bicongenic rats were crossed with the parental H-Tx strain. It is concluded that the genetic and epigenetic factors contributing to severe hydrocephalus in the H-Tx strain are more complex than originally anticipated.

Cerebrospinal Fluid Research aims to provide a specialist platform for high quality articles on all aspects of the cerebrospinal fluid (CSF), bringing together experts working in the field and promoting synthesis and dialogue. This, launch Editorial provides an overview of the field, some history, and highlights some of the journal policies.

Congenital hydrocephalus is a serious neurological disorder with a diverse etiology. Although there is strong evidence for genetic causes, few genes have been identified in humans. The rodent model, the H-Tx rat, has hydrocephalus with an onset in late gestation and a complex mode of inheritance. Ventricular dilatation is associated with abnormalities in the cerebral aqueduct and subcommissural organ. Quantitative trait locus (QTL) mapping was performed on DNA from the progeny of a backcross with the non-hydrocephalic Fischer F344 strain, using DNA microsatellite markers. The hydrocephalus trait was quantified by measuring the severity of the ventricular dilatation. Four chromosomes, each with a locus for hydrocephalus (Chrs 9, 10, 11, and 17), were mapped using additional markers and DNA from four subsets of backcross progeny with allelic recombination at or near each locus. The genetic positions for the markers and the loci were located using the Ensemble Rat Genome Browser. For each chromosome studied, the interval containing the locus was examined for known rat genes and for human genes identified from human-rat homology. Genes expressed in brain and with a function associated with known causes of hydrocephalus were identified as possible candidate genes. Future studies to characterize the causative genes in this animal model will improve the understanding of genetic causes in humans.

The H-Tx rat has fetal-onset hydrocephalus associated with closure of the cerebral aqueduct and a reduction in the secretory cells of the subcommissural organ (SCO), a circumventricular organ situated in the dorsal wall of the cerebral aqueduct. The objective of this study was to determine the role of the SCO in hydrocephalus pathogenesis. Serial brain sections through aqueduct regions containing the SCO from H-Tx rats, together with non-hydrocephalic Fischer F344 rats, were studied at E16, before hydrocephalus onset, at E17, the beginning of onset, and at P0 when the hydrocephalus was overt. Tissues were immunostained by AFRU, an antibody against the SCO glycoprotein, and for the intermediate filament nestin. The area of SCO cells with AFRU immunostaining and the severity of lateral ventricle dilatation were quantified by image analysis. At E16 all fetuses had distinct SCO ependymal cells, open aqueducts and normal lateral ventricles. The H-Tx fetuses fell into two groups with large areas and small areas of AFRU immunoreactivity, all with a full complement of SCO cells. By E17, fetuses with small areas of immunoreactivity had reduced numbers of tall SCO secretory cells, and most had aqueducts closed posteriorly and dilated ventricles. Three additional fetuses with small areas of immunoreactivity had narrow but patent aqueducts and normal ventricles, and another had an open aqueduct and dilated ventricles. At P0, pups previously identified as hydrocephalic had small areas of AFRU immunoreactivity, an aqueduct that was closed anteriorly but open posteriorly, ventricular dilatation, and an absence of SCO secretory cells. The aqueduct even when closed was lined by typical ependymal cells throughout. Decreased nestin immunostaining accompanied the SCO changes. It is concluded that reduced SCO glycoprotein immunoreactivity precedes both aqueduct closure and expansion of the lateral ventricles in the H-Tx rat.

Objective: The purpose of this study was to provide information regarding the validity of using the Allen Cognitive Levels Screen (ACL-90 version) by comparing functional cognitive performance between adolescents living in the community and adolescents residing in mental health facilities., Method: Sixty-three adolescents were assessed using the ACL-90: 32 adolescents living in the community, and 28 adolescents residing in residential mental health facilities., Results: Using a one-tailed t test, performance scores for adolescents residing in the community were statistically higher than those for adolescents living in residential mental health facilities (t(34) = 4.3, p < .001)., Conclusion: This study suggests the validity of the ACL-90 as an assessment to use for screening the cognitive functional performance of adolescents.