Analysis of periosteal lesions from commingled human remains at the Xagħra Circle hypogeum reveals the first case of probable scurvy from Neolithic Malta

Funder: FP7 Ideas: European Research Council; Id: http://dx.doi.org/10.13039/100011199; Grant(s): 323727Funder: Magdalene College, University of Cambridge; Id: http://dx.doi.org/10.13039/501100000653Funder: Arts and Humanities Research Council; Id: http://dx.doi.org/10.13039/501100000267Abstract: Objectives: Palaeopathological analysis is key for characterising population health at the individual level and across large assemblages but is rarely exploited to unite the remains of disarticulated individuals. This study explores the potential for individual identification through differential diagnosis of periosteal lesions in a commingled deposit, both to ascertain the number of individuals represented and provide a differential diagnosis. Materials and Methods: The late Neolithic Xagħra Circle hypogeum on Gozo contains the remains of more than 800 individuals, most of which were transformed to a collective disarticulated assemblage. Across the excavated population, pathological observations are strikingly low. In one specific 1 × 1‐m area in a single stratigraphic context, fragmented and disarticulated cranial and post‐cranial non‐adult bones were identified that displayed periosteal new bone formation. To aid differential diagnosis, macroscopic analysis, taphonomic analysis and micro‐computed tomography (μCT) imaging were integrated. Results: This approach, when combined with osteobiographical analyses, reveals that the elements most likely derive from one individual, a young child, who presents a probable case of scurvy. The potential for micronutrient co‐morbidities are explored, but without further microscopic study it cannot be determined if this individual also experienced iron‐deficiency anaemia and/or rickets. Discussion: In the context of the Mediterranean and Europe in later prehistory, reported cases of scurvy are currently low and often reveal periods of environmental instability and resource insufficiency. Our finding of non‐adult scurvy in late 3rd millennium BC Malta contributes to a developing picture of an increasingly unstable palaeoenvironment and declining population health at this time, although it may also indicate an individual case of poor childhood health within this broader context

Long-term effects of chronic treatment for ADHD on cognition and neural development in an adolescent rat model

A thesis submitted for fulfilment of the requirements for the degree of Combined Doctor of Philosophy/Masters in Clinical Neuropsychology, Macquarie University, Dept. of Psychology, 2011.Thesis by publication.Thesis (PhD)--Macquarie University, Faculty of Human Sciences, Dept. of Psychology, 2011.Includes bibliography: p. 190-233.Introduction -- Re-evaluation of an animal model for ADHD using a free operant choice task -- A novel non-invasive oral method of administration of Methylphenidate in rats -- Long-term effects of chronic Ritalin administration on cognitive development in non-ADHD adolescent rats -- Long-term effects of chronic Ritalin administration on tyrosine hydroxylase immunostained neurons as a measure of neural development in non-ADHD adolescent rats -- The role of catecholamine receptors in impulsivity as mediated by the prefrontal cortex -- General discussion.Attention Deficit/Hyperactivity Disorder (ADHD) has become the most commonly diagnosed childhood disorder. However, ADHD diagnosis involves subjective interpretation of diagnostic criterion which could lead to misdiagnosis. ADHD symptoms are thought to arise due to irregularities in the function of the neurotransmitters dopamine and noradrenaline. In order to normalise these irregularities, powerful psychostimulant medications such as Ritalin® (methylphenidate, MPH) are front line treatments for this disorder. MPH is generally administered over long periods of time where the onset and duration of chronic treatment corresponds with significant periods in brain development and maturation. This thesis was conducted to 1) investigate the long-term effects of chronic MPH treatment during adolescence on cognitive and neural development of misdiagnosed individuals; and 2) investigate the neural mechanisms underlying MPH's impact on impulsive behaviours. -- Appropriate animal models are necessary to conduct these investigations. The Spontaneously Hypertensive rat (SHR) has been extensively studied and is a commonly used animal model for ADHD. However, the methodology of previous research was recently criticized by Alsop (2007). The aim of the first experimental chapter of this thesis (Chapter 2) was to re-assess the validity of the SHR as an animal model of ADHD, in light of Alsop's criticisms. The results showed that the SHR had increased locomotor activity and were more sensitive to increases in delay in an impulsivity task when compared to the control strain, Wistar-Kyoto rats (WKY). These findings provide further support for the SHR as a valid animal model of ADHD. -- Previous pre-clinical research has employed drug administration methods which limit the generalisation of their findings to the human condition. When children are treated with MPH they receive low oral doses, whilst the majority of pre-clinical research administers large doses of MPH via intraperitoneal injection. The aim of the second experimental study (Chapter 3) was to develop an oral method of drug administration that was less invasive than dosing by gavage and that required minimal training. For this, the rats learned to consume a MPH suspension through a drinking spout. Following this novel oral drug administration, there was a dose-dependent increase in locomotor activity that was similar in effect to MPH administration by gavage. -- The following experimental study (Chapter 4) incorporated this novel oral administration method to assess the long-term effects on cognitive development of chronic MPH treatment during adolescence. While the animal model of ADHD is the SHR, the focus of this study was on the WKY as the non-ADHD or misdiagnosed strain. The rats were orally treated with either MPH or distilled water over 4 weeks throughout adolescence (PND 27 - 52). MPH was administered twice daily to model clinical dosing schedules in children. Locomotor activity was measured at the beginning of each week of treatment and cognitive-behavioural tests were completed in adulthood after cessation of treatment. The findings of this study suggest there are enduring behavioural changes in adulthood when rats inappropriately received chronic MPH treatment throughout adolescence. However, when chronic MPH treatment was appropriately given to the ADHD rats, there were no long-term effects observed in adulthood. -- The effects of chronic MPH treatment on neural development were assessed in the following study (Chapter 5). Following 4 weeks of MPH treatment, immunostaining for Tyrosine Hydroxylase (TH) positive neurons in the prefrontal cortex (PFC) was performed at 3 stages. Group 1 and Group 2 were euthanized 1 week and 12 weeks, respectively, after cessation of treatment for neural tissue analysis. Group 3 (from Chapter 4) were euthanized upon completion of cognitive-behavioural testing for neural tissue analysis (12 weeks post treatment). The results suggest that pre-exposure to MPH in non-ADHD rats may interfere with the maturation of the PFC and may subsequently alter future neural adaptations to behavioural experiences. -- The final experimental chapter of this thesis was conducted to elaborate on the neurochemistry which may underlie the persistent behavioural changes in the adult WKY. Specifically, the final study investigated the role of dopamine and noradrenaline on impulsivity mediated by regions within the PFC (Chapter 6). Alterations in impulsivity were assessed following local infusions of dopamine antagonists or noradrenaline agonists into regions of the PFC. The results indicated that blockade of different dopamine receptors increased impulsivity depending on their location within the PFC, while noradrenaline receptor activation of the PFC was found to have no impact on impulsivity. -- In conclusion, using a method of drug administration that closely models clinical treatment in children, the findings of this thesis suggests inappropriate chronic childhood treatment with MPH has long-term effects on cognition and may interfere with brain maturation. Furthermore, the potential cause of these deficits may be alterations in DA functioning. The findings of this thesis highlight the need for more stringent diagnostic criteria for ADHD.Mode of access: World Wide Web.Some parts were removed due to copyright restrictions.xxii, 236 p. col. il

Re-evaluation of an animal model for ADHD using a free-operant choice task

Previous research using free-operant procedures have reported that the Spontaneously Hypertensive Rat (SHR) is more impulsive and inattentive than the Wistar-Kyoto (WKY) rat. Recently these behavioural differences have been suggested to be a consequence of differences in the overall activity of these strains. This study compared SHRs to WKYs on locomotor activity and delay sensitivity using a delayed reinforcement (DR) and extinction (EXT) task. SHRs maintained higher locomotor activity than WKYs, however no significant group differences were found on the total lever presses in the DR or EXT tasks. During the DR task, SHRs shifted to selecting the immediate small reinforcer significantly faster than WKYs as the delay increased. WKYs predominantly selected the lever previously associated with the delayed large reinforcer throughout the EXT task, while the SHRs showed no such preference. The significant group differences found on lever selection during the DR and EXT tasks suggests that SHRs are more sensitive to delays, therefore providing further support for the face validity of the SHR as an animal model of ADHD.6 page(s

Catecholamine receptors differentially mediate impulsive choice in the medial prefrontal and orbitofrontal cortex

Impulsivity is characteristic of several mental health disorders and is largely mediated by the prefrontal cortex subregions: the medial prefrontal cortex (mPFC) and the orbitofrontal cortex (OFC). Dopamine (DA) and norepinephrine (NE) are known to modulate activity of the prefrontal cortex, however their direct role in impulsive choice is not known. The aim of the present study was to investigate the effect of microinjecting DA or NE compounds in the mPFC or OFC on impulsive choice as measured by a delayed reinforcement (DR) task in male Wistar Kyoto rats. Following training in the DR task, rats were pretreated with DA D1 and D2 receptor antagonists (SCH23390 3 μg/side, raclopride 3 or 6 μg/side) or NE α1 and α2 receptor agonists (phenylephrine 0.1 or 0.3 μg/side, guanfacine 1 or 3 μg/side, respectively) into the mPFC or OFC and the effect on impulsive behavior was assessed. Pretreatment with raclopride into the mPFC or OFC significantly increased impulsive choice, however only pretreatment with SCH23390 into the mPFC, and not the OFC, significantly increased impulsive choice. Pretreatment with the NE receptor agonists had no effect on impulsive choice. This study suggests that DA receptors, but not NE receptors, differentially mediate impulsive choice in sub-regions of the prefrontal cortex.10 page(s

Taking the first step: protocol for a cluster randomised implementation trial comparing strategies on access to exercise programmes for people with knee osteoarthritis

Introduction This cluster randomised implementation trial will assess the effect of two behavioural change interventions on the proportion of people with structural knee osteoarthritis (OA) referred and attending exercise-based professionals (physiotherapists and exercise physiologists). The interventions are designed to increase awareness of guidelines, benefits and access pathways for exercise therapy. We hypothesise either strategy will result in more people with knee OA being referred and attending physiotherapy/exercise physiology than current standard of care.Methods and analysis We will recruit 30 radiology clinics. 10 clinics will be randomly assigned to each trial arm with 1020 people with knee OA consecutively recruited (102 people per practice) into each arm. Intervention arm 1 is an educational reminder message targeted at primary care practitioners with a hyperlink to national guidelines regarding knee OA clinical management. It will be included in the reporting template of a plain knee X-ray. Intervention arm 2 is the reminder message and a patient-facing infographic explaining the benefits and access pathways for exercise. Both interventions will be delivered once, by the radiology clinics, when a person undergoes plain X-ray for non-traumatic knee pain/dysfunction. The primary outcome is referral to physiotherapist/exercise physiology. The secondary outcome is attendance to that appointment. Both outcomes are self-reported via an online survey administered 4 weeks after the X-ray. Additional survey questions explore facilitators and barriers to appointment attendance and acceptability of the interventions. A subsample of the intervention groups will be recruited for semistructured telephone-based interviews to further explore these latter outcomes.Ethics and dissemination The study protocol was approved by Macquarie University Human Research Ethics Committee (#520221190343842) and prospectively registered with the Australian New Zealand Clinical Trials Registry. The findings of the trial will be disseminated through peer-reviewed scientific journals and conferences. We will engage with Australian physician colleges and main-stream media to distribute findings.Trial registration number ACTRN12622001414707p

Proteomic analysis of the dorsal and ventral hippocampus of rats maintained on a high fat and refined sugar diet

The typical Western diet, rich in high saturated fat and refined sugar (HFS), has been shown to increase cognitive decline with aging and Alzheimer's disease, and to affect cognitive functions that are dependent on the hippocampus, including memory processes and reversal learning. To investigate neurophysiological changes underlying these impairments, we employed a proteomic approach to identify differentially expressed proteins in the rat dorsal and ventral hippocampus following maintenance on an HFS diet. Rats maintained on the HFS diet for 8 weeks were impaired on a novel object recognition task that assesses memory and on a Morris Water Maze task assessing reversal learning. Quantitative label-free shotgun proteomic analysis was conducted on biological triplicates for each group. For the dorsal hippocampus, 59 proteins were upregulated and 36 downregulated in the HFS group compared to controls. Pathway ana-lysis revealed changes to proteins involved in molecular transport and cellular and molecular signaling, and changes to signaling pathways including calcium signaling, citrate cycle, and oxidative phosphorylation. For the ventral hippocampus, 25 proteins were upregulated and 27 downregulated in HFS fed rats. Differentially expressed proteins were involved in cell-to-cell signaling and interaction, and cellular and molecular function. Changes to signaling pathways included protein ubiquitination, ubiquinone biosynthesis, oxidative phosphorylation, and mitochondrial dysfunction. This is the first shotgun proteomics study to examine protein changes in the hippocampus following long-term consumption of a HFS diet, identifying changes to a large number of proteins including those involved in synaptic plasticity and energy metabolism. All MS data have been deposited in the ProteomeXchange with identifier PXD000028.16 page(s

Long-term effects of chronic oral Ritalin administration on cognitive and neural development in adolescent Wistar Kyoto rats

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Oxytocin directly administered into the nucleus accumbens core or subthalamic nucleus attenuates methamphetamine-induced conditioned place preference

Accumulating evidence indicates that the neuropeptide oxytocin (OXY) may modulate reward-related behavioural responses to methamphetamine (METH) administration. Limited research has examined the effect of OXY on METH-induced conditioned place preference (CPP) and little is known about the neural mechanisms involved. A Fos immunohistochemistry study recently demonstrated that peripheral OXY administration reduced METH-induced Fos expression within the nucleus accumbens (NAc) core and subthalamic nucleus (STh) in rats. The current study aimed to (i) investigate the effect of systemically administered OXY on METH-induced CPP, (ii) determine the effectiveness of a single-trial CPP procedure with METH, in order to (iii) evaluate whether pretreatment with OXY injected directly into the NAc core or the STh attenuates METH-induced CPP. Results showed that male Sprague Dawley rats learned to associate unique compartmental cues with METH (1. mg/kg, i.p.) such that they spent more time in the METH-paired compartment and less time in the saline-paired compartment. Pretreatment with systemic OXY (0.6. mg, i.p.), or OXY (0.6. ng, i.c.) microinjected into the NAc core or the STh prior to METH administration attenuated the formation of a CPP to METH. This provides further evidence that OXY acts within either the NAc core or the STh to reduce the rewarding effects of METH administration.9 page(s

Dental modification in the Circle: shaping bodies, shaping culture in Neolithic Malta

The ERC-funded FRAGSUS Project (Fragility and sustainability in small island environments: adaptation, culture change and collapse in prehistory, 2013–18) led by Caroline Malone has focused on the unique Temple Culture of Neolithic Malta and its antecedents. This third volume builds on the achievements of Mortuary customs in prehistoric Malta, published by the McDonald Institute in 2009. It seeks to answer many questions posed, but left unanswered, of the more than 200,000 fragments of mainly commingled human remains from the Xagħra Brochtorff Circle on Gozo. The focus is on the interpretation of a substantial, representative subsample of the assemblage, exploring dentition, disease, diet and lifestyle, together with detailed understanding of chronology and the affinity of the ancient population associated with the ‘Temple Culture’ of prehistoric Malta. The first studies of genetic profiling of this population, as well as the results of intra-site GIS and visualization, taphonomy, health and mobility, offer important insights into this complex mortuary site and its ritual. Remarkable evidence on the bioanthropology of care practised by these populations, together with a relatively low level of interpersonal violence, and examples of longevity, reveal new aspects about the Neolithic Maltese. Detailed case studies employing computerized tomography describe disease such as =scurvy and explore dietary issues, whilst physical activity and body size have been assessed through biomechanical analysis, supported by taphonomic study, isotopic analyses, a review of mortuary practices during prehistory and a robust new chronology. The results form a rich contextualized body of material that advances understanding of cultural change within the context of small island insularity, and provides biological comparisons for the graphic figurative art of early Malta. These data and the original assemblage are conserved in the National Museum of Archaeology in Valletta as a resource for future study.This project has received funding from the European Research Council (ERC) under the European Union’s Seventh Framework Programme (FP7-2007-2013) (Grant agreement No. 323727)