Re-examining the Mysterious Role of the Cerebellum in Pain.

Pain is considered a multidimensional experience that embodies not merely sensation, but also emotion and perception. As is appropriate for this complexity, pain is represented and processed by an extensive matrix of cortical and subcortical structures. Of these structures, the cerebellum is gaining increasing attention. Although association between the cerebellum and both acute and chronic pain have been extensively detailed in electrophysiological and neuroimaging studies, a deep understanding of what functions are mediated by these associations is lacking. Nevertheless, the available evidence implies that lobules IV-VI and Crus I are especially pertinent to pain processing, and anatomical studies reveal that these regions connect with higher-order structures of sensorimotor, emotional, and cognitive function. Therefore, we speculate that the cerebellum exerts a modulatory role in pain via its communication with sites of sensorimotor, executive, reward, and limbic function. On this basis, in this review, we propose numerous ways in which the cerebellum might contribute to both acute and chronic pain, drawing particular attention to emotional and cognitive elements of pain. In addition, we emphasise the importance of advancing our knowledge about the relationship between the cerebellum and pain by discussing novel therapeutic opportunities that capitalize on this association.

The Impact of Expert Opinions in COVID-19 News Coverage on Vaccination During the Fifth Outbreak in Hong Kong: A Time Series Analysis.

The role of experts in news coverage has become increasingly prominent, but the evidence regarding the effectiveness of expert opinions in affecting public behavior remains mixed. This study seeks to examine the influence of expert opinions covered in the news on the public's response to public health crises. By adopting a macro-level framing perspective, we investigated how framing consistency, a macro-level concept indicating the agreement between expert opinions in news coverage and government policies or among peer experts, evolves over time and its temporal causal relationship with public behavior. Specifically, this study collected all press news coverage in Hong Kong over four months during the fifth outbreak, including 1,416 articles with 650 expert opinions, as well as the vaccination data that paralleled with this period. We constructed time series of expert opinions and vaccination behavior, and then conducted Vector Autoregressive (VAR) models with Granger causality analysis to examine how framing consistency of expert opinions in news coverage influenced vaccination. The results indicate that the consistent framing between expert opinions and government policies increased COVID-19 vaccination during the fifth outbreak in Hong Kong, while conflicting opinions responding to government policies had no significant effect on vaccination. Opinions among medical experts on COVID-19 issues also did not significantly impact vaccination. The implications for designing communication strategies and enhancing public behavioral support during public health crises are discussed.

Improving Quality Metrics with a Day-only Skin Abscess Protocol: Experience from Australia.

BACKGROUND: Skin abscesses are a common emergency presentation often requiring incision and drainage; however, issues with theatre access lead to delays in management and high costs. The long-term impact in a tertiary centre of a standardised day-only protocol is unknown. The aim was to evaluate the impact of day-only skin abscess protocol (DOSAP) for emergency surgery of skin abscesses in a tertiary institution in Australia and to provide a blueprint for other institutions. METHODS: A retrospective cohort study analysed several time periods: Period A (July 2014 to 2015, n = 201) pre-DOSAP implementation, Period B (July 2016 to 2017, n = 259) post-DOSAP, and Period C (July 2018 to 2022, n = 1,625) prospectively analysed four 12-month periods to assess long-term utilisation of DOSAP. Primary outcomes were length of stay and delay to theatre. Secondary outcome measures included theatre start time, representation rates and total costs. Statistical analysis using nonparametric methods was used to analyse the data. RESULTS: There was a significant decrease in ward length of stay (1.25 days vs. 0.65 days, P < 0.0001), delay to theatre (0.81 days vs. 0.44 days, P < 0.0001) and theatre start time before 10AM (44 cases vs. 96 cases, P < 0.0001) after implementation of DOSAP. There was a significant decrease in median cost of admission of $711.74 after accounting for inflation. Period C reported 1,006 abscess presentations successfully managed by DOSAP over the four-year period. CONCLUSION: Our study demonstrates the successful implementation of DOSAP in an Australian tertiary centre. The ongoing utilisation of the protocol demonstrates the ease of applicability.

Improving Body Satisfaction Through Fitness App Use: Explicating the Role of Social Comparison, Social Network Size, and Gender.

Body dissatisfaction is prevalent worldwide, fueling the highly lucrative diet and plastic surgery industry, with many adverse outcomes. Yet, limited attention has been dedicated to noninvasive interventions that effectively enhance body satisfaction. We argue that, by altering the target of the social comparison process, people can shift their focus from body appearance to physical activity level. The present study investigated whether social comparison in terms of physical activity level provided by fitness apps could affect users' body satisfaction. A survey was conducted with 643 users of WeRun, the Chinese leading mobile fitness app. Subsequent analyses revealed that both upward and downward social comparison mediated the positive relationship between fitness app use and body satisfaction. Moreover, the users' social network size and gender played a moderating role in the social comparison processes. Fitness app use was positively related to downward comparison for male users; social network size moderated the relationship between fitness app use and upward comparison for female users. The utility of fitness apps in mitigating body dissatisfaction is also discussed.

Repeat mild traumatic brain injuries (RmTBI) modify nociception and disrupt orexinergic connectivity within the descending pain pathway.

Repeat mild traumatic brain injuries (RmTBI) result in substantial burden to the public health system given their association with chronic post-injury pathologies, such as chronic pain and post-traumatic headache. Although this may relate to dysfunctional descending pain modulation (DPM), it is uncertain what mechanisms drive changes within this pathway. One possibility is altered orexinergic system functioning, as orexin is a potent anti-nociceptive neuromodulator. Orexin is exclusively produced by the lateral hypothalamus (LH) and receives excitatory innervation from the lateral parabrachial nucleus (lPBN). Therefore, we used neuronal tract-tracing to investigate the relationship between RmTBI and connectivity between lPBN and the LH, as well as orexinergic projections to a key site within the DPM, the periaqueductal gray (PAG). Prior to injury induction, retrograde and anterograde tract-tracing surgery was performed on 70 young-adult male Sprague Dawley rats, targeting the lPBN and PAG. Rodents were then randomly assigned to receive RmTBIs or sham injuries before undergoing testing for anxiety-like behaviour and nociceptive sensitivity. Immunohistochemical analysis identified distinct and co-localized orexin and tract-tracing cell bodies and projections within the LH. The RmTBI group exhibited altered nociception and reduced anxiety as well as a loss of orexin cell bodies and a reduction of hypothalamic projections to the ventrolateral nucleus of the PAG. However, there was no significant effect of injury on neuronal connectivity between the lPBN and orexinergic cell bodies within the LH. Our identification of structural losses and the resulting physiological changes in the orexinergic system following RmTBI begins to clarify acute post-injury mechanistic changes that drive may drive the development of post-traumatic headache and the chronification of pain.

Anionic amino acids support hydrolysis of poly-ß-(1,6)-N-acetylglucosamine exopolysaccharides by the biofilm dispersing glycosidase Dispersin B.

The exopolysaccharide poly-ß-(1→6)-N-acetylglucosamine (PNAG) is a major structural determinant of bacterial biofilms responsible for persistent and nosocomial infections. The enzymatic dispersal of biofilms by PNAG-hydrolyzing glycosidase enzymes, such as Dispersin B (DspB), is a possible approach to treat biofilm-dependent bacterial infections. The cationic charge resulting from partial de-N-acetylation of native PNAG is critical for PNAG-dependent biofilm formation. We recently demonstrated that DspB has increased catalytic activity on de-N-acetylated PNAG oligosaccharides, but the molecular basis for this increased activity is not known. Here, we analyze the role of anionic amino acids surrounding the catalytic pocket of DspB in PNAG substrate recognition and hydrolysis using a combination of site-directed mutagenesis, activity measurements using synthetic PNAG oligosaccharide analogs, and in vitro biofilm dispersal assays. The results of these studies support a model in which bound PNAG is weakly associated with a shallow anionic groove on the DspB protein surface with recognition driven by interactions with the -1 GlcNAc residue in the catalytic pocket. An increased rate of hydrolysis for cationic PNAG was driven, in part, by interaction with D147 on the anionic surface. Moreover, we identified that a DspB mutant with improved hydrolysis of fully acetylated PNAG oligosaccharides correlates with improved in vitro dispersal of PNAG-dependent Staphylococcus epidermidis biofilms. These results provide insight into the mechanism of substrate recognition by DspB and suggest a method to improve DspB biofilm dispersal activity by mutation of the amino acids within the anionic binding surface.

Development of a GalNAc-Tyrosine-Specific Monoclonal Antibody and Detection of Tyrosine O-GalNAcylation in Numerous Human Tissues and Cell Lines.

Glycosylation is a vital post-translational modification involved in a range of biological processes including protein folding, signaling, and cell-cell interactions. In 2011, a new type of O-linked glycosylation was discovered, wherein the side-chain oxygen of tyrosine is modified with a GalNAc residue (GalNAc-Tyr). At present, very little is known about GalNAc-Tyr prevalence, function, or biosynthesis. Herein, we describe the design and synthesis of a GalNAc-Tyr-derived hapten and its use in generating a GalNAc-Tyr selective monoclonal antibody. The antibody, G10C, has an unusually high affinity (app KD = 100 pM) and excellent selectivity for GalNAc-Tyr. We also obtained a crystal structure of the G10C Fab region in complex with 4-nitrophenyl-N-acetyl-α-d-galactosaminide (a small molecule mimic of GalNAc-Tyr) providing insights into the structural basis for high affinity and selectivity. Using this antibody, we discovered that GalNAc-Tyr is widely expressed in most human tissues, indicating that it is a ubiquitous and underappreciated post-translational modification. Localization to specific cell types and organ substructures within those tissues indicates that GalNAc-Tyr is likely regulated in a cell-specific manner. GalNAc-Tyr was also observed in a variety of cell lines and primary cells but was only present on the external cell surface in certain cancer cell lines, suggesting that GalNAc-Tyr localization may be altered in cancer cells. Collectively, the results shed new light on this under-studied form of glycosylation and provide access to new tools that will enable expanded biochemical and clinical investigations.

Are vancomycin dosing guidelines followed? A mixed methods study of vancomycin prescribing practices.

AIMS: Despite the availability of international consensus guidelines, vancomycin dosing and therapeutic drug monitoring (TDM) remain suboptimal. This study aimed to assess concordance of vancomycin dosing and TDM with institutional guidelines and to identify factors taken into consideration by clinicians when prescribing vancomycin. METHODS: A retrospective audit of 163 patients receiving vancomycin therapy (≥48 hours) was undertaken. Data collected included patient characteristics, dosing history and plasma vancomycin and creatinine concentrations. Concordance of dosing and TDM with institutional guidelines was evaluated. Semi-structured interviews, including simulated prescribing scenarios, were undertaken with prescribers (n = 17) and transcripts analysed. RESULTS: Plasma vancomycin concentrations (n = 1043) were collected during 179 courses of therapy. Only 24% of courses commenced with a loading dose with 72% lower than recommended. The initial maintenance dose was concordant in 42% of courses with 34% lower than recommended. Only 14% of TDM samples were trough vancomycin concentrations. Dose was not adjusted for 60% (21/35) of subtherapeutic and 43% (18/42) of supratherapeutic trough vancomycin concentrations, respectively. Interview participants reported that patient characteristics (including renal function), vancomycin concentrations, guidelines and expert advice influenced vancomycin prescribing decisions. Despite referring to guidelines when completing simulated prescribing scenarios, only 37% of prescribing decisions aligned with guideline recommendations. CONCLUSION: Poor compliance with institutional vancomycin guidelines was observed, despite prescriber awareness of available guidelines. Multifaceted strategies to support prescriber decision-making are required to improve vancomycin dosing and monitoring.

A Colorimetric Assay to Enable High-Throughput Identification of Biofilm Exopolysaccharide-Hydrolyzing Enzymes.

Glycosidase enzymes that hydrolyze the biofilm exopolysaccharide poly-ß-(1→6)-N-acetylglucosamine (PNAG) are critical tools to study biofilm and potential therapeutic biofilm dispersal agents. Function-driven metagenomic screening is a powerful approach for the discovery of new glycosidase but requires sensitive assays capable of distinguishing between the desired enzyme and functionally related enzymes. Herein, we report the synthesis of a colorimetric PNAG disaccharide analogue whose hydrolysis by PNAG glycosidases results in production of para-nitroaniline that can be continuously monitored at 410 nm. The assay is specific for enzymes capable of hydrolyzing PNAG and not related ß-hexosaminidase enzymes with alternative glycosidic linkage specificities. This analogue enabled development of a continuous colorimetric assay for detection of PNAG hydrolyzing enzyme activity in crude E. coli cell lysates and suggests that this disaccharide probe will be critical for establishing the functional screening of metagenomic DNA libraries.

Decreased pallidal vesicular monoamine transporter type 2 availability in Parkinson's disease: The contribution of the nigropallidal pathway.

To date, the contribution of the nigropallidal pathway degeneration to Parkinson's disease (PD) motor symptoms has received little attention and is generally poorly understood in spite of solid evidence that the globus pallidus (GP) receives a dense neuronal projection from the substantia nigra. To explore the dopaminergic (DA) changes of the GP in PD, we measured the availability of vesicular monoamine transporter 2 (VMAT2) using [11C]DTBZ and positron emission tomography in 30 PD patients and 12 controls. PD patients were classified in two groups based on severity of disease. VMAT2 reduction was found to be significant in the external GP (GPe) regardless of the disease stage, while the internal GP (GPi) showed reduction only in more severe patients. Pallidal VMAT2 binding correlated with dopaminergic changes in the striatum, with the GPe showing a stronger association than GPi. Our findings showed DA terminals in the GPe and GPi may be differentially vulnerable in different stages of the disease, possibly playing a distinctive role in the development of motor complications with GPi DA deficiency contributing more to later-stage symptoms.

Chronic fluoxetine treatment accelerates kindling epileptogenesis in mice independently of 5-HT2A receptors.

Patients with epilepsy often have mood disorders, and these are commonly treated with antidepressant drugs. Although these drugs are often successful in mitigating depressive symptoms, how they affect the epileptogenic processes has been little studied. Recent evidence has demonstrated that treatment with selective serotonin reuptake inhibitor (SSRI) antidepressant drugs adversely promotes epileptogenesis, which may be of great concern considering the number of patients exposed to these drugs. This study investigated 5-HT2A receptor signaling as a potential mechanism driving the pro-epileptogenic effects of the prototypical SSRI fluoxetine. Male homozygous 5-HT2A receptor knockout mice or wild-type littermates (n = 9-14/group) were treated with continuous fluoxetine (10 mg kg-1 d-1 , sc) or vehicle and subjected to electrical kindling of the amygdala. Compared to vehicle, fluoxetine treatment accelerated kindling epileptogenesis (P < .001), but there was no effect of genotype (P = .75), or any treatment x genotype interaction observed (P = .90). Of interest, fluoxetine treatment increased afterdischarge thresholds in both genotypes (P = .007). We conclude that treatment with fluoxetine promotes epileptogenesis in mice, but this effect is not mediated by 5-HT2A receptors. This suggests that antidepressants may accelerate the onset of acquired epilepsy in patients who have experienced epileptogenic cerebral insults.

Fatigue in Parkinson's disease: The contribution of cerebral metabolic changes.

Fatigue is a common and disabling non-motor symptom in Parkinson's disease associated with a feeling of overwhelming lack of energy. The aim of this study was to identify the neural substrates that may contribute to the development of fatigue in Parkinson's disease. Twenty-three Parkinson's disease patients meeting UK Brain Bank criteria for the diagnosis of idiopathic Parkinson's disease were recruited and completed the 2-[18 F]fluoro-2-deoxy-D-glucose (FDG)-PET scan. The metabolic activities of Parkinson's disease patients with fatigue were compared to those without fatigue using statistical parametric mapping analysis. The Parkinson's disease group exhibiting higher level of fatigue showed anti-correlated metabolic changes in cortical regions associated with the salience (i.e., right insular region) and default (i.e., bilateral posterior cingulate cortex) networks. The metabolic abnormalities detected in these brain regions displayed a significant correlation with level of fatigue and were associated with a disruption of the functional correlations with different cortical areas. These observations suggest that fatigue in Parkinson's disease may be the expression of metabolic abnormalities and impaired functional interactions between brain regions linked to the salience network and other neural networks. Hum Brain Mapp 38:283-292, 2017. © 2016 Wiley Periodicals, Inc.

Exploring cytologic features and potential diagnostic challenges of metastatic NUT carcinoma to the parotid gland: A case report and a comprehensive literature review.

NUT carcinoma (NC) is a highly aggressive, poorly differentiated carcinoma that harbors a t(15:19) translocation, leading to the fusion of the NUTM1 gene. While the upper aerodigestive tract along the midline (head, neck, thorax, and mediastinum) is commonly reported as the primary site of NC, subsequent cases have emerged in diverse locations. Achieving a definitive diagnosis based solely on morphology is challenging; however, it can be achieved using immunohistochemistry (IHC) specific to the NUT antibody or by demonstrating the characteristic BRD4::NUTM1 fusion. Accurate and timely diagnosis can potentially inform patient management and guide treatment. While histologic documentation of NC is commonly found, there is a limited description of its cytologic features. A 39-year-old male with a history of sinonasal squamous cell carcinoma (SCC) presented with a right parotid mass aspirated via fine needle aspiration cytology (FNA). Histologic examination of the previous sinonasal pathology reviewed at our institution revealed sheets of primitive-appearing, monotonous, undifferentiated cells with distinct, prominent nucleoli. Additionally, there were foci of abrupt keratinization, accompanied by a notable neutrophilic infiltrate. The initial diagnosis of SCC was reclassified to NC and confirmed through NUT IHC and molecular testing. Although the parotid FNA initially suggested the possibility of a variety of small round blue cell tumors, it exhibited morphological similarities to the sinonasal tumor, leading to the diagnosis of metastatic NC. Cytomorphologic features of NC are limited and can overlap with various small round blue cell tumors. Correct classification is especially pivotal in the era of targeted therapy, considering the ongoing development and evaluation of BET inhibitors targeting BRD4.

Is dog walking suitable for physical activity promotion? Investigating the exercise intensity of on-leash dog walking.

Background: Approximately a quarter of the global population is physically inactive, increasing the prevalence of chronic health conditions such as cardiovascular disease. Clearly, a population shift is needed to increase physical activity participation. Given almost half of American and Australian households have at least one dog, dog walking has the potential to increase physical activity. The objective of this study was to characterize the exercise intensity of dog walking using physiological measures to determine whether it achieved a threshold for health-enhancement. Method: From February 2020 to September 2022, dog owners (aged > 18 years, without impediment to walking) who resided in metropolitan Sydney participated in an on-leash dog walk for a minimum of 20 minutes, while wearing a heart rate monitor and carrying a phone to track cadence, route and duration. Results: Forty-three participants were recruited (aged 34.26 ± 16 years). Data from measures of %heart rate reserve (38 ± 10.8 %HRR), %heart rate max (61 ± 7.2 %HRmax) and average cadence (45 ± 8.4steps/min) classified dog-walking as light intensity. However, when using average walking speed (4.29 ± 0.8 km/hr) and metabolic equivalents (3.53 ± 0.6METs), the walk was classified as moderate intensity. Conclusion: Overall, depending on the intensity measure used, dog walking was positioned in the upper range of light intensity and the lower range of moderate intensity. Although dog walking at a certain intensity may be difficult to prescribe as strategy for meeting current moderate-to-vigorous focused physical activity recommendations, it should be recognised as a beneficial activity that may reach moderate intensity on some occasions.

Microbiome depletion prior to repeat mild TBI differentially alters social deficits and prefrontal cortex plasticity in adolescent and adult rats.

Although aging, repeat mild traumatic brain injury (RmTBI), and microbiome modifications independently change social behavior, there has been no investigation into their cumulative effects on social behavior and neuroplasticity within the prefrontal cortex. Therefore, we examined how microbiome depletion prior to RmTBI affected social behavior and neuroplasticity in adolescent and adult rats. Play, temperament analysis, elevated plus maze, and the hot/cold plate assessed socio-emotional function. Analyses of perineuronal nets (PNNs) and parvalbumin (PV) interneurons was completed. Social-emotional deficits were more pronounced in adults, with microbiome depletion attenuating social behavior deficits associated with RmTBI in both age groups. Microbiome depletion increased branch length and PNN arborization within the PFC but decreased the overall number of PNNs. Adults and males were more vulnerable to RmTBI. Interestingly, microbiome depletion may have attenuated the changes to neuroplasticity and subsequent social deficits, suggesting that the microbiome is a viable, but age-specific, target for RmTBI therapeutics.

Tau Phosphorylation Patterns in the Rat Cerebral Cortex After Traumatic Brain Injury and Sodium Selenate Effects: An Epibios4rx Project 2 Study.

Sodium selenate (SS) activates protein phosphatase 2 (PP2A) and reduces phosphorylated tau (pTAU) and late post-traumatic seizures after lateral fluid percussion injury (LFPI). In EpiBioS4Rx Project 2, a multi-center international study for post-traumatic targets, biomarkers, and treatments, we tested the target relevance and modification by SS of pTAU forms and PP2A and in the LFPI model, at two sites: Einstein and Melbourne. In Experiment 1, adult male rats were assigned to LFPI and sham (both sites) and naïve controls (Einstein). Motor function was monitored by neuroscores. Brains were studied with immunohistochemistry (IHC), Western blots (WBs), or PP2A activity assay, from 2 days to 8 weeks post-operatively. In Experiment 2, LFPI rats received SS for 7 days (SS0.33: 0.33 mg/kg/day; SS1: 1 mg/kg/day, subcutaneously) or vehicle (Veh) post-LFPI and pTAU, PR55 expression, or PP2A activity were studied at 2 days and 1 week (on treatment), or 2 weeks (1 week off treatment). Plasma selenium and SS levels were measured. In Experiment 1 IHC, LFPI rats had higher cortical pTAU-Ser202/Thr205-immunoreactivity (AT8-ir) and pTAU-Ser199/202-ir at 2 days, and pTAU-Thr231-ir (AT180-ir) at 2 days, 2 weeks, and 8 weeks, ipsilaterally to LFPI, than controls. LFPI-2d rats also had higher AT8/total-TAU5-ir in cortical extracts ipsilateral to the lesion (WB). PP2A (PR55-ir) showed time- and region-dependent changes in IHC, but not in WB. PP2A activity was lower in LFPI-1wk than in sham rats. In Experiment 2, SS did not affect neuroscores or cellular AT8-ir, AT180-ir, or PR55-ir in IHC. In WB, total cortical AT8/total-TAU-ir was lower in SS0.33 and SS1 LFPI rats than in Veh rats (2 days, 1 week); total cortical PR55-ir (WB) and PP2A activity were higher in SS1 than Veh rats (2 days). SS dose dependently increased plasma selenium and SS levels. Concordant across-sites data confirm time and pTAU form-specific cortical increases ipsilateral to LFPI. The discordant SS effects may either suggest SS-induced reduction in the numbers of cells with increased pTAU-ir, need for longer treatment, or the involvement of other mechanisms of action.

An unexpected case of Castleman disease in porta hepatis lymphadenopathy.

Castleman disease (CD) is a rare lymphoproliferative disorder that can be life threatening if left unmanaged in severe cases of inflammatory response. CD should be excluded by thorough workup in cases of lymphadenopathy and splenomegaly of unknown cause. Excisional biopsy of lymph nodes may be required to make a definitive diagnosis. A case of CD manifesting as portal hepatis lymphadenopathy is presented.

Lower trapezius muscle function in people with and without shoulder and neck pain: a systematic review.

CONTEXT: Shoulder and neck pain are leading causes of disability worldwide. Rotator cuff pathology has strong associations with such pain and is extensively targeted by healthcare practitioners. A dysfunctional lower trapezius muscle has also been shown to contribute to neck and shoulder pain, yet it is often overlooked. OBJECTIVES: This systematic review analyzes those with a history of, or who are currently managing, shoulder or neck pain to indicate differences in measures of lower trapezius function when compared to subjects without that pain. METHODS: Studies with no age restrictions were included in the study. Studies could determine lower trapezius muscle function with any quantifiable measurement tool or clinical assessment. If the study included a control group (no pain) and a comparator group (pain), and if lower trapezius muscle function was assessed in both, the study was typically included. The significance of the lower trapezius muscle function change was summarized in these pain patients. From a final total of 18 studies identified, level of muscle activity, muscle activation, time to onset, muscle strength, and muscle thickness were reported. RESULTS: The 18 included articles involved 485 participants with shoulder and/or neck pain and 455 without. Half of the shoulder pain studies (6/12), and all of the neck pain studies (6/6), demonstrated that the lower trapezius had a noticeable impact. The lower trapezius muscle in participants with shoulder and neck pain tended to show decreased muscle strength, and decreased time to onset/latency. CONCLUSIONS: The findings from this systematic review should be taken into consideration when assessing and treating patients with shoulder and neck pain. Future studies that define the type and duration of shoulder and neck pain, as well as prospectively assessing lower trapezius muscle function in those with and without that pain, are needed.

Repetitive mild traumatic brain injury alters central and peripheral clock gene expression in the adolescent rat.

Mild traumatic brain injury (mTBI) or concussion is a common injury worldwide leading to substantial medical costs and a high burden on society. In adolescents, falls and sports related trauma are often the causes of mTBI. Importantly, critical brain growth and development occurs during this sensitive period making the prospect of a brain injury a worrying phenomenon. Upwards of 70% of patients report circadian disruption following these injuries and this has been shown to impede recovery. Therefore, we sought to determine if core circadian clock gene expression was disrupted in rat model of repetitive mTBI (RmTBI). Male and female adolescent rats (n = 129) received sham or RmTBI. The animals were then euthanized at different times throughout the day and night. Tissue from the hypothalamus, cerebellum, hippocampus, liver, and small intestine were evaluated for the expression of per1, per2, cry1, clock, bmal1 and rev-erb-α. We found most clock genes varied across the day/night indicating circadian expression patterns. In the hypothalamus we found RmTBI altered the expression of cry1 and bmal1 in addition to sex differences in per2, cry1, clock, bmal1 and rev-erb- α. In the cerebellum, per1, per2, cry1, clock, bmal1 and rev-erb-α rhythms were all knocked out by RmTBI in addition to sex differences in cry1, clock and bmal1 expression. We also detected a significant decrease in overall expression of all clock genes in males in the middle of the night. In the hippocampus we found that RmTBI changed the rhythm of rev-erb-α expression in addition to sex differences in bmal1 expression. In the liver we detected strong rhythms in all genes examined, however only per2 expression was knocked out by RmTBI, in addition we also detected sex differences in per2 and cry1. We also detected an overall decrease in female clock gene expression in the early night. In the small intestine, RmTBI altered cry1 expression and there were sex differences in rev-erb-α. These results indicate that RmTBI alters core circadian clock gene expression in the central and peripheral nervous system in a time, tissue and sex dependent manner. This may be disrupting important phase relationships between the brain and peripheral nervous system and contributing to post-injury symptomology and also highlights the importance for time and sex dependent assessment of injury outcomes.

Gene expression changes in the cerebellum are associated with persistent post-injury pain in adolescent rats exposed to early life stress.

Chronic pain develops following injury in approximately 20% of adolescents, at twice the rate in females than males. Adverse childhood experiences also increase the risk for poor health outcomes, such as chronic pain. Emerging literature suggests the cerebellum to be involved in pain processing, however detailed explorations into how the cerebellum contributes to pain are lacking. Therefore, this study aimed to characterise chronic pain outcomes and cerebellar gene expression changes following early life stress and injury in both sexes. The adverse childhood experience of neglect was modelled using a maternal separation (MS) paradigm, which was combined with a subsequent injury (mild traumatic brain injury (mTBI) or plantar incision surgery) in adolescent male and female Sprague-Dawley rats. We measured behavioural nociceptive sensitivity, systemic modulators of pain such as calcitonin gene-related protein (CGRP) and Substance P, as well as gene expression of IL1ß, GFAP, GR, MR, GABRA1, CNR1, MAOA, and DAT1 in the cerebellum to examine associations between pain and neuroinflammation, the stress response, inhibitory neurotransmission, and monoaminergic function. We found increases in mechanical nociceptive sensitivity following plantar incision surgery. Sex differences were observed in anxiety-like behaviour and neuroinflammation, whereas systemic pain modulators showed cumulative effects with the addition of stressors. Most interestingly however, the increases in nociceptive sensitivity were associated with the suppressed expression of cerebellar genes that regulate stress, inhibition, cannabinoid function, and dopaminergic function, alongside sex-dependent distinctions for genes involved in inflammation and injury. This study highlights a novel link between nociception and molecular function in the cerebellum. Further investigation into how the cerebellum contributes to pain in males and females will facilitate novel therapeutic insights and opportunities.