Proteolytic processing of SDF-1alpha reveals a change in receptor specificity mediating HIV-associated neurodegeneration

Proteolytic cleavage of constitutively expressed proteins can generate peptides with novel bioactive properties. Matrix metalloproteinase (MMP)-2 cleaves the 4 amino-terminal residues of the chemokine, stromal cell-derived factor (SDF)-1alpha, yielding a highly neurotoxic molecule, SDF(5-67), which fails to bind to its cognate receptor, CXCR4. Herein, we detected SDF(5-67) in brain monocytoid cells of HIV-infected persons, particularly in those with HIV-associated dementia. SDF(5-67) activated cell type-specific expression of proinflammatory genes including IL-1beta, TNFalpha, indoleamine 2',3'-dioxygenase (IDO), and IL-10 in both astrocytic and monocytoid cells (P < 0.05). Unlike SDF-1alpha, SDF(5-67) caused neuronal membrane perturbations with ensuing neurotoxicity and apoptosis (P < 0.05) through engagement of an inducible receptor. CXCR3 antagonists and siRNA-mediated knockdown of CXCR3 inhibited SDF(5-67)-stimulated neurophysiological changes, neuronal death, and neuroimmune activation (P < 0.05). Moreover SDF(5-67) bound directly to CXCR3 in a competitive manner, mediated by its amino terminus. In vivo neuroinflammation, neuronal loss, and neurobehavioral abnormalities caused by SDF(5-67) (P < 0.05) were prevented by a CXCR3 antagonist. These studies reveal additive neuropathogenic properties exerted by a proteolytically cleaved chemokine as consequences of a change in receptor specificity, culminating in neurodegeneration.

Effect of word and syllable frequency on activation during lexical decision and reading aloud

This functional MRI (fMRI) study investigated the effect of lexical and syllable frequency on visual word processing during lexical decision and reading aloud. Previous research has shown a dissociation of syllable and word frequency effects in Spanish using behavioral and electrophysiological measures, suggesting that sublexical (syllabic) representations are computed and mediate the firing of lexical candidates. Here, we characterize the neuroanatomical basis of these lexical and sublexical manipulations and their dependence on task. During lexical decision, words with low vs. high lexical frequency increased activation in left frontal, anterior cingulate, supplemental motor area (SMA), and pre-SMA regions; while words with high vs. low syllable frequency increased activation in a left anterior inferior temporal region. In contrast, when the words were read aloud those with low vs. high syllable frequency increased activation in the left anterior insula, with no other significant effects. On the basis of the neuroanatomy, we propose that the contrasting effects of syllable frequency during lexical decision and reading aloud reflect two different cognitive processes in visual word processing. Specifically, words with high-frequency syllables may increase lexical competition in the inferior temporal lobe while facilitating articulatory planning in the left anterior insula.

The impact of foster care on development

Foster care is a protective intervention designed to provide out of home placement to children living in at-risk home environments. This study employs prospective longitudinal data (N = 189) to investigate the effects of foster care on the development of child behavior and psychological functioning taking into account baseline adaptation prior to placement and socioeconomic status at the time of placement. Comparisons were made among three groups: children who experienced foster care, those who were maltreated but remained in the home, and children who had not experienced foster care or maltreatment despite their similarly at-risk demographic characteristics. In the current sample, children placed in out of home care exhibited significant behavior problems in comparison to children who received adequate care, and using the same pre- and postplacement measure of adaptation, foster care children showed elevated levels of behavior problems following release from care. Similarly, children placed into unfamiliar foster care showed higher levels of internalizing problems compared with children reared by maltreating caregivers, children in familiar care, and children who received adequate caregiving. Findings suggest that outcomes related to foster care may vary with type of care and beyond the effects associated with maltreatment history, baseline adaptation, and socioeconomic status.

Religion, spirituality and the well-being of informal caregivers: a review, critique, and research prospectus

The purpose of this article is to review and critique the published literature examining the relationships between religion/spirituality and caregiver well-being and to provide directions for future research. A systematic search was conducted using bibliographic databases, reference sections of articles, and by contacting experts in the field. Articles were reviewed for measurement, theoretical, and design limitations. Eighty-three studies were retrieved. Research on religion/spirituality and caregiver well-being is a burgeoning area of investigation; 37% of the articles were published in the last five years. Evidence for the effects of religion/spirituality were unclear; the preponderance (n = 71, 86%) of studies found no or a mixed association (i.e., a combination of positive, negative, or non-significant results) between religion/spirituality and well-being. These ambiguous results are a reflection of the multidimensionality of religion/spirituality and the diversity of well-being outcomes examined. They also partially reflect the frequent use of unrefined measures of religion/spirituality and of atheoretical approaches to studying this topic. Investigators have a fairly large number of studies on religion/spirituality and caregiver well-being on which to build. Future studies should be theory driven and utilize psychometrically sound measures of religion/spirituality. Suggestions are provided to help guide future work.

Acceptance of pneumococcal vaccine under standing orders by race and ethnicity

PURPOSE

To assess whether and how pneumococcal vaccine acceptance occurs after nurse recommendation varies by race/ethnicity.

METHODS

We prospectively evaluated nurses' standing orders to assess and vaccinate high-risk patients in a general medicine practice.

RESULTS

Of 370 adult patients surveyed (60% nonwhite), 78 (21%) declined vaccination following nurse recommendation, and 43 (12%) persisted in declining after physician consultation. Three-hundred-twenty-seven (88%) patients accepted vaccination: 292 (79%) accepted following nurse recommendation and 35 (9%) following physician consultation. African Americans (19%) were significantly more likely to decline compared with whites (8%) and Asians (5%) (P= 0.01). Reasons for refusal included believing vaccination was unnecessary (32%), fearing shots in general (21%), fearing vaccine-induced illness (26%) and wanting more informotion regarding the vaccine (9%).

CONCLUSION

Standing orders, physicians' firm recommendations and addressing patients' vaccine-related concerns may reduce racial/ethnic disparities in vaccination.

A randomized trial of the efficacy of group therapy in changing viral load and CD4 counts in individuals living with HIV infection

OBJECTIVE

This randomized pilot study evaluates whether seropositive patients who are randomly assigned to receive a supportive-expressive group therapy plus education intervention show greater improvements in increased immune function and decreased viral load compared to those randomly assigned to an education-only intervention.

METHOD

Fifty-nine individuals who had been HIV-seropositive for at least 6 months prior to inclusion in the study and had been receiving standard pharmacologic treatment were entered in a prospective randomized trial of the effects of weekly supportive-expressive group therapy on changes in immune status. Participants were matched for AIDS status and sex and randomized to receive weekly sessions of group psychotherapy plus educational materials on HIV/AIDS, or to receive the educational materials alone. Participants were assessed before treatment and then 12 weeks later.

RESULTS

Individuals who were randomized to group therapy showed a statistically significant increase in CD4 count and decrease in HIV viral load. Among individuals randomized to the education only condition, no significant change occurred in CD4 count or viral load.

CONCLUSIONS

These results provide preliminary data suggesting that HIV-seropositive individuals who receive supportive-expressive group psychotherapy may experience concomitant improvements in CD4 cell count and viral load. Further research with a larger sample should examine the possible underlying mechanisms of such benefits.

Reducing alcohol-exposed pregnancy risk in college women: initial outcomes of a clinical trial of a motivational intervention

A significant number of college women are at risk for alcohol-exposed pregnancy (AEP) owing to binge drinking paired with using contraception ineffectively. This article describes a randomized controlled trial of a one-session motivational interviewing-based intervention to reduce AEP risk among college women and presents 1-month outcomes demonstrating the early impact of this intervention. There were 228 female students from a mid-Atlantic urban university enrolled in the trial. Eligibility criteria were being in the age range of 18-24 years and being at risk for AEP. Risk for AEP was defined as having sexual intercourse with a man in the past 90 days while using contraception ineffectively (no use, incorrect use of an effective method, or use of an ineffective method only); drinking at risky levels was defined as engaging in at least one binge in the past 90 days or consuming an average of eight standard drinks per week. One-month outcome data were available for 212 of the 228 enrolled women (a follow-up rate of 93%), with complete data available for 105 women assigned to the control condition and 94 assigned to the intervention condition. At 1-month follow-up, 15% of the control subjects and 25% of the intervention women reported no risk drinking, a significant difference favoring the intervention group. Significantly fewer control subjects (48%) used effective contraception at 1-month follow-up as compared with intervention women (64%), chi(2)(1) = 5.1, p < .03. Significantly more intervention women (74%) were no longer at risk for AEP at 1 month as compared with control subjects (54%), chi(2)(1) = 8.15, p < .005. Factors that were associated with continued AEP risk at 1-month follow-up were a higher number of standard drinks per day consumed in the month prior to baseline (odds ratio, 1.1) and assignment to the control condition (odds ratio, 2.9). The risks of unintended pregnancy and AEP among drinking women in college merit greater prevention efforts. The results of this study show the promise of one preventive intervention that warrants additional study.

Preparedness for the Death of a Loved One and Mental Health in Bereaved Caregivers of Patients with Dementia: Findings from the REACH Study

BACKGROUND

Although it has been suggested that family and friends who are prepared for the death of a loved one have less distress, the relationship between preparedness and bereavement mental health is inconclusive.

OBJECTIVES

To determine the relationship between preparedness for the death and mental health in bereaved caregivers of dementia patients and explore predictors of preparedness.

DESIGN

A prospective study of family caregivers of persons with dementia. Standardized assessment instruments and structured questions were used to collect data at study entry and at 6, 12, and 18 months. Multiple caregiving-related variables were collected. Bereaved caregivers reported whether they were "not at all" prepared or prepared for the death of their loved one.

SUBJECTS

Two hundred twenty-two bereaved caregivers

RESULTS

Twenty-three percent of caregivers were not prepared for the death. These caregivers had more depression, anxiety, and complicated grief symptoms. Black caregivers, caregivers with less education, those with less income, and those with more depressive symptoms prior to the death were more likely to perceive themselves as "not at all" prepared. In contrast, the amount of pain the care recipient was in prior to death was positively associated with preparedness.

CONCLUSIONS

Despite providing high-intensity care, often for years, many bereaved caregivers perceived themselves as unprepared for the death. These caregivers had more depression, anxiety, and complicated grief symptoms. Future work should be directed to confirming these findings and determining how best to intervene with high-risk caregivers.

LONI visualization environment

Over the past decade, the use of informatics to solve complex neuroscientific problems has increased dramatically. Many of these research endeavors involve examining large amounts of imaging, behavioral, genetic, neurobiological, and neuropsychiatric data. Superimposing, processing, visualizing, or interpreting such a complex cohort of datasets frequently becomes a challenge. We developed a new software environment that allows investigators to integrate multimodal imaging data, hierarchical brain ontology systems, on-line genetic and phylogenic databases, and 3D virtual data reconstruction models. The Laboratory of Neuro Imaging visualization environment (LONI Viz) consists of the following components: a sectional viewer for imaging data, an interactive 3D display for surface and volume rendering of imaging data, a brain ontology viewer, and an external database query system. The synchronization of all components according to stereotaxic coordinates, region name, hierarchical ontology, and genetic labels is achieved via a comprehensive BrainMapper functionality, which directly maps between position, structure name, database, and functional connectivity information. This environment is freely available, portable, and extensible, and may prove very useful for neurobiologists, neurogenetisists, brain mappers, and for other clinical, pedagogical, and research endeavors.

Sources of situational variation in ethnic identity and psychological well-being: a Palm Pilot study of Chinese American students

Experience sampling reports collected randomly six times a day for 1 week examined the association between context, ethnic salience, psychological well-being, and stable ethnic centrality and ethnic private regard among Chinese American university students (N = 62). At the level of the situation, ethnic composition, family, and language were associated with higher ethnic salience. Stable ethnic centrality moderated the association between ethnic salience and family where higher centrality was related to stronger ethnic salience when students were with family. At the situation level, ethnic salience was associated with fewer depressive symptoms and increased positive mood. Stable ethnic private regard moderated this association where higher private regard was related to fewer depressive symptoms and higher levels of positive mood when ethnicity was salient.

mGluR2 acts through inhibitory Galpha subunits to regulate transmission and long-term plasticity at hippocampal mossy fiber-CA3 synapses

Presynaptic inhibitory G protein-coupled receptors play a critical role in regulating transmission at a number of synapses in the central and peripheral nervous system. We generated transgenic mice that express a constitutively active form of an inhibitory Galpha subunit to examine the molecular mechanisms underlying the actions of one such receptor, metabotropic glutamate receptor (mGluR) 2, at mossy fiber-CA3 synapses in the hippocampus. mGluR2 participates in at least three types of mossy fiber synaptic plasticity, (i) transient suppression of synaptic transmission, (ii) long-term depression (LTD), and (iii) inhibition of long-term potentiation (LTP), and we find that inhibitory Galpha signaling is sufficient to account for the actions of mGluR2 in each. The fact that constitutively active Galphai2 occludes the transient suppression of synaptic transmission by mGluR2, while enhancing LTD, suggests further that these two forms of plasticity are expressed via different mechanisms. In addition, the LTP deficit observed in constitutively active Galphai2-expressing mice suggests that mGluR2 activation may serve as a metaplastic switch to permit the induction of LTD by inhibiting LTP.

LRRK2 expression linked to dopamine-innervated areas

OBJECTIVE

Leucine-rich repeat kinase 2 (LRRK2) has been linked to Parkinson's disease. Our study explores the expression of LRRK2 in human and rodent brain tissue.

METHODS

We analyzed LRRK2 gene activity at the cellular level using in situ hybridization.

RESULTS

We found a high and strikingly specific expression of LRRK2 mRNA in rodent striatum and parts of cortex and no signals in dopamine neurons. In human tissue, LRRK2 mRNA was found in the corresponding brain areas caudatus and putamen at lower levels and dopamine neurons were also devoid of LRRK2 mRNA. Expression levels in striatal tissue did not differ between Parkinson's disease patients and control subjects.

INTERPRETATION

Unlike all other genes so far linked to Parkinson's disease, our results demonstrate that LRRK2 expression is particularly high in brain dopaminoceptive areas.

A wavelet-based statistical analysis of FMRI data: I. motivation and data distribution modeling

We propose a new method for statistical analysis of functional magnetic resonance imaging (fMRI) data. The discrete wavelet transformation is employed as a tool for efficient and robust signal representation. We use structural magnetic resonance imaging (MRI) and fMRI to empirically estimate the distribution of the wavelet coefficients of the data both across individuals and spatial locations. An anatomical subvolume probabilistic atlas is used to tessellate the structural and functional signals into smaller regions each of which is processed separately. A frequency-adaptive wavelet shrinkage scheme is employed to obtain essentially optimal estimations of the signals in the wavelet space. The empirical distributions of the signals on all the regions are computed in a compressed wavelet space. These are modeled by heavy-tail distributions because their histograms exhibit slower tail decay than the Gaussian. We discovered that the Cauchy, Bessel K Forms, and Pareto distributions provide the most accurate asymptotic models for the distribution of the wavelet coefficients of the data. Finally, we propose a new model for statistical analysis of functional MRI data using this atlas-based wavelet space representation. In the second part of our investigation, we will apply this technique to analyze a large fMRI dataset involving repeated presentation of sensory-motor response stimuli in young, elderly, and demented subjects.

Premotor neuronal plasticity in monkeys adapting to a new dynamic environment

Recent evidence indicates that premotor cortex (PM) in addition to their well-established motor functions, also play a role in nonmotor processes such as spatial attention and working memory. In the present study, neuronal activities in dorsal PM (PMd) and ventral PM (PMv) were recorded in a force field adaptation task. This study found that PM neurons show learning-related plasticity and that a neuron demonstrates either one type or multiple types of properties (i.e. kinematic, dynamic, and memory). The current study reveals that memory properties could be displayed by one or a combination of the cell activity parameters [i.e. average firing rate (AFR), dynamic range (DR), and preferred direction (PD)]. A predominant percentage of cells displayed memory properties with AFR or AFR plus other parameters. This study investigated the memory properties vs. the time sequence of the task trial [i.e. delay time (DT), movement time (MT), and target holding time (THT)] and found that: (i) most neurons display memory properties only in one time window; (ii) few neurons display memory properties in three time windows, and (iii) there are significantly more cells showing memory properties during MT than during any other time windows. There are cells that show memory I (changing their tuning curves in the force field and retaining those changes after the force field was removed), memory II (changing their tuning curves after the force field was removed), or both properties. Significantly more cells display one type of memory property (memory I or memory II) rather than both types of memory properties (memory I and memory II).

Coping strategies of HIV patients with peripheral neuropathy

The aim of this study was to evaluate the association between coping strategies and reports of with pain and distress in patients with HIV-related peripheral neuropathy. Seventy-eight HIV seropositive subjects completed the Coping Strategies Questionnaire (CSQ), a self-report measure that assesses seven factors, the Brief Pain Inventory (BPI), the Brief Symptom Inventory (BSI) and the Beck Depression Inventory (BDI). Bivariate correlations revealed that younger patients used more Praying-Hoping (r=-.23, p<.04) and Catastrophizing (r=-.30, p<.007). t-tests demonstrated that women used more Praying-Hoping (t(76) = 3.42, p<.01), while Hispanic and African American patients used more Praying-Hoping more than Caucasians (F (1,77) = 22.11, p=.0005). Catastrophizing significantly predicted higher scores on the BDI (t=2.968, p=.004), the Global Severity Index (GSI) of the Brief Symptom Inventory BSI (t=2.400, p=.02); and pain interference on the Brief Pain Inventory BPI (t=2.996, p=.004) controlling for age, gender, and ethnic background. These results demonstrate that coping strategies may differ according to age, gender, and ethnic background in an HIV population, and that Catastrophizing predicts distress and interference with functioning in this sample.

Neuronal correlates of movement dynamics in the dorsal and ventral premotor area in the monkey

We investigated how neurons in the different motor areas of the frontal lobe reflect the movement dynamics, and how their neuronal activity undergoes plastic changes when monkeys adapt to perturbing forces (they learn new dynamics). Here we describe the results obtained in the dorsal premotor area (PMd) and ventral premotor area (PMv). Monkeys performed visually instructed, delayed reaching movements before, during and after exposure and adaptation to a viscous, curl force field. During movement planning (i.e., during an instructed delay that followed the cue and preceded the go signal), we found dynamics-related activity in PMd but not in PMv. A closer analysis revealed that the population of PMd reflected the dynamics of the upcoming movement increasingly over the course of the delay, starting from a kinematics-related signal. During movement execution, dynamics-related activity was present in both PMd and PMv. In this respect, the results for PMd were similar to that previously found for the supplementary motor area (SMA) whereas the results for PMv were more similar to that previously found for the primary motor cortex (M1). Plastic changes associated with the acquisition of new dynamics found in PMd and PMv were qualitatively similar to those previously observed in M1 and SMA. The ensemble of our experiments suggest a broader picture of the cortical control of movements, whereby multiple areas all contribute to the various sensorimotor processes, including "low" computations such as the movement dynamics, but also express a degree of specialization.

fMRI Hippocampal Activity During a VirtualRadial Arm Maze

Numerous studies have shown that the hippocampus is critical for spatial memory. Within nonhuman research, a task often used to assess spatial memory is the radial arm maze. Because of the spatial nature of this task, this maze is often used to assess the function of the hippocampus. Our goal was to extrapolate this task to humans and examine whether healthy undergraduates utilize their hippocampus while performing a virtual reality version of the radial arm maze task. Thirteen undergraduates performed a virtual radial arm maze during functional magnetic resonance imaging. The brain maps of activity reveal bilateral hippocampal BOLD signal changes during the performance of this task. However, paradoxically, this BOLD signal change decreases during the spatial memory component of the task. Additionally, we note frontal cortex activity reflective of working memory circuits. These data reveal that, as predicted by the rodent literature, the hippocampus is involved in performing the virtual radial arm maze in humans. Hence, this virtual reality version may be used to assess the integrity of hippocampus so as to predict risk or severity in a variety of psychiatric disorders.

14-3-3 protein in CSF: an early predictor of SIV CNS disease

In neurons, 14-3-3 proteins regulate diverse processes, including signal transduction, neurotransmitter production, and apoptosis by binding to target proteins, but the role 14-3-3 proteins play in the pathogenesis of central nervous system (CNS) disease remains unclear. To examine the relationship between presence of 14-3-3 protein in cerebrospinal fluid (CSF) and encephalitis in the SIV/macaque model of HIV CNS disease, CSF levels of 14-3-3 protein were measured by quantitative immunoblotting throughout infection in 6 SIV-infected pigtailed macaques. Beginning during asymptomatic infection and continuing until death, CSF levels of 14-3-3 were elevated in 4 of 6 SIV-infected animals. Animals with 14-3-3 protein in CSF had the highest viral loads in the CSF after acute infection and the highest levels of both viral RNA and protein in brain (p < 0.001). In contrast, the presence of 14-3-3 protein in CSF was not associated with CNS microglial/macrophage activation measured by quantitative immunohistochemical staining for CD68 (p = 0.13). CSF levels of 14-3-3 protein may be a valuable marker of early neuronal damage, CNS viral replication, and CNS disease progression in HIV-infected individuals.

Violence Perpetration Among Urban American Indian Youth

OBJECTIVE

To predict the likelihood of violence perpetration given various combinations of the most statistically salient risk and protective factors related to violence perpetration.

DESIGN

Urban Indian Youth Health Survey, conducted from October 9, 1995, to March 30, 1998, consisting of 200 forced-choice items exploring values, cultural identity, relationships, decision-making skills, and health and well-being.

SETTING

Urban schools and an after-school youth development program at an urban American Indian center.

PARTICIPANTS

Five hundred sixty-nine urban American Indian youth enrolled in grades 3 through 12.

MAIN OUTCOME MEASURES

Violence perpetration dichotomized in 2 ways: (1) level of violence perpetration (ie, hitting someone 1-2 times in the past year vs picking fights, hitting repeatedly, participating in group fights, or shooting or stabbing someone in the past year) and (2) having shot and/or stabbed someone during the past year.

RESULTS

In the final multivariate models with age as a covariate, most protective against violence perpetration were connections to school (odds ratio [OR], 0.17), positive affect (OR, 0.29), and peer prosocial behavior norms against violence (OR, 0.35). School connectedness (OR, 0.01) and positive affect (OR, 0.46) were also protective against shooting and/or stabbing someone, as was parental prosocial behavior norms against violence (OR, 0.23). The strongest risk factors for violence perpetration were substance use (OR, 2.60) and suicidal thoughts/behaviors (OR, 2.71); for shooting and/or stabbing, it was substance use (OR, 5.26). The likelihood of violence perpetration increased markedly (from 10% to 85%) as the exposure to risk factors increased and protective factors decreased. For shooting or stabbing someone, the probabilities ranged from 3% (0 risks and 3 protective factors) to 64% (1 risk and 0 protective factors).

CONCLUSION

The dramatic reduction in the likelihood of violence involvement when risk was offset with protective factors in the probability profiles suggests the utility of a dual strategy of reducing risk while boosting protection.

Intergenerational transmission of role reversal between parent and child: Dyadic and family systems internal working models

The current study examined the intergenerational transmission of role reversal within a developmental psychopathology framework. Role reversal is a relationship disturbance in which a parent looks to a child to meet the parent's need for comfort, parenting, intimacy, or play, and the child attempts to meet these needs. In a normative sample, n=138, fathers and mothers reported on childhood role reversal with their mothers as part of the Adult Attachment Interview, AAI (George, Kaplan, & Main, 1984). Mother-child role reversal was then assessed in an observational paradigm when children were 2 years of age. Based on theories of dyadic and family systems internal working models we hypothesized gender specific replications of role reversal in the next generation. Indeed, mothers who reported role reversal with their mothers during the AAI tended to engage in higher levels of role reversal with their toddler-aged daughters. Furthermore, when fathers reported role reversal with their mothers during the AAI, mothers tended to engage in higher levels of role reversal with their toddler-aged sons. The importance of the inclusion of fathers in family research, the relationship between role reversal and attachment, and implications for preventive interventions are discussed.

Optimizing the fMRI data-processing pipeline using prediction and reproducibility performance metrics: I. A preliminary group analysis

We argue that published results demonstrate that new insights into human brain function may be obscured by poor and/or limited choices in the data-processing pipeline, and review the work on performance metrics for optimizing pipelines: prediction, reproducibility, and related empirical Receiver Operating Characteristic (ROC) curve metrics. Using the NPAIRS split-half resampling framework for estimating prediction/reproducibility metrics (Strother et al., 2002), we illustrate its use by testing the relative importance of selected pipeline components (interpolation, in-plane spatial smoothing, temporal detrending, and between-subject alignment) in a group analysis of BOLD-fMRI scans from 16 subjects performing a block-design, parametric-static-force task. Large-scale brain networks were detected using a multivariate linear discriminant analysis (canonical variates analysis, CVA) that was tuned to fit the data. We found that tuning the CVA model and spatial smoothing were the most important processing parameters. Temporal detrending was essential to remove low-frequency, reproducing time trends; the number of cosine basis functions for detrending was optimized by assuming that separate epochs of baseline scans have constant, equal means, and this assumption was assessed with prediction metrics. Higher-order polynomial warps compared to affine alignment had only a minor impact on the performance metrics. We found that both prediction and reproducibility metrics were required for optimizing the pipeline and give somewhat different results. Moreover, the parameter settings of components in the pipeline interact so that the current practice of reporting the optimization of components tested in relative isolation is unlikely to lead to fully optimized processing pipelines.

Pulsatile luteinizing hormone disruption in depression

Two independent groups recently published data comparing pulsatile luteinizing hormone (LH) release between depressed and control women. Despite similar populations and LH sampling frequency, they reached different conclusions: Meller et al. [Am. J. Psych. 154 (1997) 1454] found disruption of normal LH pulsatility in depressed women, whereas Young et al. [Arch. Gen. Psych. 57 (2000) 1157] did not. To resolve this discrepancy, the current study applies a single, well-established statistical method, spectral analysis, to the two data sets and concludes that both depressed populations display significantly altered LH pulsatile release.

Hippocampal volume, memory, and cortisol status in major depressive disorder: effects of treatment

BACKGROUND

Depression has been linked to stress, memory deficits, and hypercortisolemia. However, the relationships between depression, hippocampal structure and function, and cortisol levels are unclear and the effects of antidepressant treatment on the measures are not well studied.

METHODS

Whole hippocampal volume, performance on verbal and visual declarative memory function and cortisol status was evaluated in 38 subjects with major depressive disorder (MDD) and 33 healthy subjects. All measures were repeated in a subgroup (n = 22) of depressed patients after successful selective serotonin reuptake inhibitor (SSRI) treatment.

RESULTS

Hippocampal volume was not significantly different between patients with untreated MMD and healthy subjects, after controlling for whole brain volume, age and gender. However, depressed subjects had significantly greater deficits in delayed memory and percent retention on the verbal portion of the Wechsler Memory Scale-Revised (WMS-R) compared with healthy subjects, without significant differences in visual memory, attention, vigilance, or distractibility. Baseline plasma or urinary free cortisol (UFC) was not related to either hippocampal volume or memory deficits. Successful treatment with antidepressants did not change hippocampal volume but did result in a significant improvement in memory function and a reduction in UFC excretion.

CONCLUSIONS

Medication-free nonelderly depressed outpatients without alcohol dependence or adverse experiences in childhood had normal hippocampal volume. Focal declarative memory deficits in depression supported localized hippocampal dysfunction in depressed patients. Treatment with antidepressants significantly improved memory and depression but did not alter hippocampal volume, suggesting that antidepressants may improve hippocampal function in the absence of detectable structural changes.

Sex differences and correlations in a virtual Morris water task, a virtual radial arm maze, and mental rotation☆

Different tasks are often used to assess spatial memory in humans compared to nonhumans. In order to bridge this paradigmatic gap, we used a within-subject design to test 61 undergraduates on three spatial memory tasks. One of these tasks, the Vanderberg 3D mental rotation task, is classically used to assess spatial memory in humans. The other two tests are virtual analogues of two tasks used classically to assess spatial memory in rodents: the Morris water task and an eight-arm radial maze. We find that males perform significantly better than females on the mental rotation task and in finding a hidden platform in the virtual Morris water task. Moreover, during a probe trial, males spend significantly more distance of their swim in the training quadrant, but males and females do not differ in navigating to a visible platform. However, for the virtual eight-arm radial maze, there is no sex difference in working memory errors, reference memory errors, or distance to find the rewards. Surprisingly, an examination of the correlations among the three tasks indicates that only mental rotation ability and Morris water task probe trial performance correlate significantly among the three tasks (i.e. there are no significant correlations with traditional measures the tasks, e.g. time or distance to completion). Hence, the Morris water task and the eight-arm radial maze do not assess spatial memory in the same manner, and even after equating factors such as motivation, stress, and motor demands, there still are procedural demands of the tasks that reinforce differential strategy selection during spatial memory. This suggests that caution should be taken when utilizing these two tasks interchangeable as tests of spatial memory.

A test of the generality of perceptually based categories found in infants: attentional differences toward natural kinds by New World monkeys

A preference to novelty paradigm used to study human infants (Quinn, 2002) examined attention to novel animal pictures at subordinate, basic and superordinate levels in tamarins. First, pairs of pictures were presented in phases, starting with a monkey species (subordinate level) and ending with mammal and dinosaur sets (superordinate levels). After each phase, tests paired novel pictures from the familiarized set with a novel broader category. Look rates toward each picture were coded. Tamarins looked significantly longer at a novel species after being familiarized with a monkey species, a species-specific effect. Subjects attended equivalently to novel primate species after habituation to four monkey species, but looked significantly longer at pictures of mammals, marking a more global-level inclusion and exclusion. Superordinate testing revealed that more novel and diverse sets were differentiated attentionally. The evidence implies that natural categorical representation occurs at an attentional level in primates in ways similar to human infants, and is affected by recent exposure and category variability.