Synaptic alterations in the rTg4510 mouse model of tauopathy

Synapse loss, rather than the hallmark amyloid‐β (Aβ) plaques or tau‐filled neurofibrillary tangles (NFT), is considered the most predictive pathological feature associated with cognitive status in the Alzheimer's disease (AD) brain. The role of Aβ in synapse loss is well established, but despite data linking tau to synaptic function, the role of tau in synapse loss remains largely undetermined. Here we test the hypothesis that human mutant P301L tau overexpression in a mouse model (rTg4510) will lead to age‐dependent synaptic loss and dysfunction. Using array tomography and two methods of quantification (automated, threshold‐based counting and a manual stereology‐based technique) we demonstrate that overall synapse density is maintained in the neuropil, implicating synapse loss commensurate with the cortical atrophy known to occur in this model. Multiphoton in vivo imaging reveals close to 30% loss of apical dendritic spines of individual pyramidal neurons, suggesting these cells may be particularly vulnerable to tau‐induced degeneration. Postmortem, we confirm the presence of tau in dendritic spines of rTg4510‐YFP mouse brain by array tomography. These data implicate tau‐induced loss of a subset of synapses that may be accompanied by compensatory increases in other synaptic subtypes, thereby preserving overall synapse density. Biochemical fractionation of synaptosomes from rTg4510 brain demonstrates a significant decrease in expression of several synaptic proteins, suggesting a functional deficit of remaining synapses in the rTg4510 brain. Together, these data show morphological and biochemical synaptic consequences in response to tau overexpression in the rTg4510 mouse model. J. Comp. Neurol., 521:1334–1353, 2013. © 2012 Wiley Periodicals, Inc.     

The effects of different recruitment and incentive strategies for body acceptance programs on college women

ABSTRACT

The objective of this study—getting individuals to participate in eating disorder prevention programs—is difficult yet crucial for dissemination efforts. Little research has investigated what incentive strategies can be particularly efficacious, and even less is published on their cost-effectiveness. The following study examined two types of email advertisements and six incentive strategies in an empirically supported body acceptance program disseminated at a large university. A total of 5,978 undergraduate women received email advertisements, of which 430 signed up to participate. An additional 588 who did not participate were assessed. Results suggest the most effective incentives were offering gift certificates for free manicure services and free personal fashion style training gift certificates from a student organization. Undergraduate women were least likely to attend due to lack of knowledge about the program, not having a friend to attend with them, or inconvenient times. Implications for future research are explored.     

Patterns of lifetime female victimisation and psychotic experiences: a study based on the UK Adult Psychiatric Morbidity Survey 2007

Purpose

Research has shown that sexual trauma represents a specific threat for psychosis, particularly among females. Sexual trauma among females, however, has also been shown to enhance the risk for further revictimisation. Females are likely to exhibit distinct lifetime trauma profiles, i.e. female sexual trauma victims are often more likely to experience particular forms of re-victimisation, such as intimate partner and domestic violence.

Methods

This study used data from the Adult Psychiatric Morbidity Survey (2007) to profile lifetime histories of sexual trauma and domestic violence among female participants (N = 4,111).

Results

The latent class analysis revealed four lifetime victimisation classes: (i) a multiple victimisation class; (ii) an intimate partner victimisation class; (iii) a sexual victimisation class; and (iv) a victimisation-free class. Multivariate logistic regression revealed that there was a strong association between class membership and a diagnosis of psychosis and that the victimisation classes were significantly associated with all psychotic-like experiences. Compared to the victimisation-free class, the multiple victimisation class displayed an increased likelihood of experiencing all psychotic experiences except mania. The intimate partner victimisation class was also associated with an increased likelihood of experiencing all psychotic experiences; however, the odds ratios for this class were lower than those recorded for the multiple victimisation class.

Conclusions

These findings reflect female-specific variation in both victimisation history and psychosis-related vulnerability. Acknowledging such sex-specific variation may advance our understanding of the complex associations that continue to emerge between trauma and psychosis for both males and females.     

Influence of a pedicle flap design on acute postoperative sequelae after lower third molar removal

Pain, swelling, trismus, and alveolar osteitis often occur after removal of impacted third molar teeth. To minimize these complications a number of mucoperiosteal flap designs have been advocated, but, to date, a pedicle flap design has not been evaluated. In a randomized prospective split mouth study, 52 participants had bilateral symmetrically impacted mandibular third molars removed over two sessions. A buccal envelope or pedicle flap was randomly assigned to the left or right third molar site. Pre-and postoperative pain and swelling were recorded using a standardized visual analogue scale, trismus was measured as the maximum inter-incisal opening distance in millimetres and dry socket was assessed clinically. Greater continuous pain, pain on maximum opening, and oro-facial swelling were recorded with the pedicle flap design. Continuous pain resolved significantly faster with this flap design (p<0.05). Trismus was similar for both flap designs (p>0.05). Five cases of alveolar osteitis occurred with the envelope flap whilst no cases developed with the pedicle flap, but the incidence was too small for statistical analysis. The pedicle flap improved some aspects of postoperative pain experience and reduced the incidence of alveolar osteitis, but further investigation with a larger sample size is required to evaluate its significance.