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1.
eNeuro ; 11(3)2024 Mar.
Article in English | MEDLINE | ID: mdl-38471779

ABSTRACT

Self-ordered sequencing is an important executive function involving planning and executing a series of steps to achieve goal-directed outcomes. The lateral frontal cortex is implicated in this behavior, but downstream striatal outputs remain relatively unexplored. We trained marmosets on a three-stimulus self-ordered spatial sequencing task using a touch-sensitive screen to explore the role of the caudate nucleus and putamen in random and fixed response arrays. By transiently blocking glutamatergic inputs to these regions, using intrastriatal CNQX microinfusions, we demonstrate that the caudate and putamen are both required for, but contribute differently to, flexible and fixed sequencing. CNQX into either the caudate or putamen impaired variable array accuracy, and infusions into both simultaneously elicited greater impairment. We demonstrated that continuous perseverative errors in variable array were caused by putamen infusions, likely due to interference with the putamen's established role in monitoring motor feedback. Caudate infusions, however, did not affect continuous errors, but did cause an upward trend in recurrent perseveration, possibly reflecting interference with the caudate's established role in spatial working memory and goal-directed planning. In contrast to variable array performance, while both caudate and putamen infusions impaired fixed array responding, the combined effects were not additive, suggesting possible competing roles. Infusions into either region individually, but not simultaneously, led to continuous perseveration. Recurrent perseveration in fixed arrays was caused by putamen, but not caudate, infusions. These results are consistent overall with a role of caudate in planning and flexible responding and the putamen in more rigid habitual or automatic responding.


Subject(s)
Callithrix , Putamen , Animals , 6-Cyano-7-nitroquinoxaline-2,3-dione/pharmacology , Corpus Striatum , Caudate Nucleus/physiology
2.
J Strength Cond Res ; 37(8): 1588-1593, 2023 Aug 01.
Article in English | MEDLINE | ID: mdl-36735295

ABSTRACT

ABSTRACT: Fernandes, JFT, Arede, J, Clarke, H, Garcia-Ramos, A, Perez-Castilla, A, Norris, JP, Wilkins, CA, and Dingley, AF. Kinetic and kinematic assessment of the band-assisted countermovement jump. J Strength Cond Res 37(8): 1588-1593, 2023-This study sought to elucidate kinetic and kinematic differences between unloaded and band-assisted countermovement jumps (CMJs). In a randomized order, 20 healthy subjects (mass 84.5 ± 18.6 kg) completed 3 repetitions of CMJs across 3 conditions: unloaded (at body mass), low, and moderate band (8.4 ± 1.9 and 13.3 ± 3.3 kg body mass reduction, respectively). For all repetitions, a force platform and linear position transducer were used to record and calculate kinetic and kinematic data. Body mass was significantly different between the unloaded, low, and moderate band conditions ( p < 0.05). Peak velocity, absolute peak, and mean force and movement duration displayed a trend that was mostly related to the condition (i.e., unloaded > low > moderate) ( p < 0.05). The opposing trend (i.e., moderate > low > unloaded) was generally observed for relative peak and mean force, reactive strength index modified, and flight time ( p < 0.05). No differences were observed for mean velocity, movement duration, and absolute and relative landing forces ( p > 0.05). The use of band assistance during CMJs can alter force, time, and velocity variables. Practitioners should be aware of the potential positive and negative effects of band assistance during CMJs.


Subject(s)
Athletic Performance , Humans , Biomechanical Phenomena , Muscle Strength , Exercise Test , Kinetics
3.
Nicotine Tob Res ; 25(3): 586-589, 2023 02 09.
Article in English | MEDLINE | ID: mdl-36239328

ABSTRACT

INTRODUCTION: E-Cigarette voucher schemes have been piloted across the UK to support populations to quit smoking. This short report evaluates a scheme that targets vulnerable and disadvantaged smokers who had failed to quit smoking by other means. METHODS: Descriptive summary evaluation of service data on smoking outcomes and qualitative data from selected participants, as "key-informants" (n = 4) and key stakeholders (stop smoking staff, vape shop staff, and general practitioners [GPs]). RESULTS: In total, 668 participants were referred to the scheme, and 340 participants redeemed a voucher. By intention to treat analysis (ITT) 143/668 (21%) were recorded as quit smoking at 4 weeks. At 12 weeks, 7.5% of participants had quit, by ITT. Overall, the pilot project was well received by clients as it offered an affordable route into vaping for smoking cessation. GPs supported the scheme and appreciated being able to offer an alternative to entrenched smokers. CONCLUSIONS: The scheme shows promise in supporting entrenched smokers to quit smoking. The offer of similar voucher schemes across the UK suggests the potential to reduce overall smoking prevalence and associated morbidity and mortality. IMPLICATIONS: Working with GPs in a deprived area, it was possible to set-up a vape shop voucher scheme for smoking cessation. Patients with comorbidities who had tried and failed to quit smoking previously were referred to receive a vape shop voucher to be redeemed for an initial starter kit, alongside support from the stop smoking service. This innovative scheme enabled 42% of entrenched smokers who redeemed a voucher to successfully quit smoking within 4 weeks.


Subject(s)
Electronic Nicotine Delivery Systems , Smoking Cessation , Vaping , Humans , Pilot Projects , Smoking , United Kingdom/epidemiology , Vaping/epidemiology
4.
Curr Res Neurobiol ; 3: 100049, 2022.
Article in English | MEDLINE | ID: mdl-36518342

ABSTRACT

Studying higher brain function presents fundamental scientific challenges but has great potential for impactful translation to the clinic, supporting the needs of many patients suffering from conditions that relate to neuronal dysfunction. For many key questions relevant to human neurological conditions and clinical interventions, non-human primates (NHPs) remain the only suitable model organism and the only effective way to study the relationship between brain structure and function with the knowledge and tools currently available. Here we present three exemplary studies of current research yielding important findings that are directly translational to human clinical patients but which would be impossible without NHP studies. Our first example shows how studies of the NHP prefrontal cortex are leading to clinically relevant advances and potential new treatments for human neuropsychiatric disorders such as depression and anxiety. Our second example looks at the relevance of NHP research to our understanding of visual pathways and the visual cortex, leading to visual prostheses that offer treatments for otherwise blind patients. Finally, we consider recent advances in treatments leading to improved recovery of movement and motor control in stroke patients, resulting from our improved understanding of brain stem parallel pathways involved in movement in NHPs. The case for using NHPs in neuroscience research, and the direct benefits to human patients, is strong but has rarely been set out directly. This paper reviews three very different areas of neuroscience research, expressly highlighting the unique insights offered to each by NHP studies and their direct applicability to human clinical conditions.

5.
Cereb Cortex ; 32(7): 1319-1336, 2022 03 30.
Article in English | MEDLINE | ID: mdl-34494095

ABSTRACT

Structural and functional abnormalities of the orbitofrontal cortex (OFC) have been implicated in affective disorders that manifest anxiety-related symptoms. However, research into the functions of primate OFC has predominantly focused on reward-oriented rather than threat-oriented responses. To redress this imbalance, the present study performed a comprehensive analysis of the independent role of 2 distinct subregions of the central OFC (anterior area 11; aOFC and posterior area 13; pOFC) in the processing of distal and proximal threat. Temporary inactivation of both aOFC and pOFC heightened responses to distal threat in the form of an unknown human, but not to proximal threat assessed in a discriminative Pavlovian conditioning task. Inactivation of the aOFC, however, did unexpectedly blunt conditioned threat responses, although the effect was not valence-specific, as conditioned appetitive responses were similarly blunted and appeared restricted to a discriminative version of the task (when both CS- and CS+ are present within a session). Inactivation of the pOFC did not affect conditioned responses to either proximal threat or reward and basal cardiovascular activity was unaffected by manipulations of activity in either subregion. The results highlight the contribution of aOFC and pOFC to regulation of responses to more distal uncertain but not proximal, certain threat and reveal their opposing contribution to that of the immediately adjacent medial OFC, area 14.


Subject(s)
Callithrix , Reward , Animals , Conditioning, Classical/physiology , Frontal Lobe/physiology , Prefrontal Cortex/physiology
6.
J Feline Med Surg ; 24(6): 587-595, 2022 06.
Article in English | MEDLINE | ID: mdl-34254845

ABSTRACT

OBJECTIVES: The aim of the study was to describe traumatic stifle injury in cats and report complications and long-term outcome. METHODS: The medical records from seven veterinary hospitals of cats treated for traumatic stifle injury were reviewed. Long-term follow-up data were collected from referring veterinarians and using the Feline Musculoskeletal Pain Index, collected from owners. RESULTS: Seventy-two cats were included in the study. The most common combination of ligament injury involved both cruciate ligaments and the lateral collateral ligament (25.4%). Medial meniscal injury was more common (66.2%) than lateral meniscal injury (59.4%). A temporary transarticular pin was used intraoperatively to aid reduction in 23/73 (31.5%) surgeries. Postoperative immobilisation was applied in 41/72 (56.9%) cats with a mean duration of 4.8 weeks. Short-term complications occurred in 40/64 (62.5%) cats. Long-term complications occurred in seven (17.5%) cats. Overall outcome was excellent in 25/61 (41%) cats, good in 13/61 (21.3%) cats, fair in 11/61 (18%) cats and poor in 12/61 (19.7%) cats. Mean length of follow-up was 29.6 months (range 0.5-204). A significantly poorer outcome was observed in cats with medial meniscal injury and those undergoing revision surgery. Use of a transarticular pin when left in situ for postoperative immobilisation was associated with a poorer outcome (P = 0.043) and a higher risk of complications (P = 0.018). Postoperative immobilisation was not related to outcome. CONCLUSIONS AND RELEVANCE: Traumatic stifle injury in cats can lead to rupture of multiple ligaments causing significant instability of the joint. Surgical treatment is associated with a high rate of short-term complications, although long-term outcome may still be good to excellent in the majority of cats (62.3%). In cats where follow-up was available, postoperative immobilisation had no positive effect on outcome and may not be required. Leaving a transarticular pin for postoperative immobilisation is not recommended as it was significantly associated with a poorer outcome and a higher complication rate.


Subject(s)
Anterior Cruciate Ligament Injuries , Cat Diseases , Joint Dislocations , Animals , Anterior Cruciate Ligament Injuries/surgery , Anterior Cruciate Ligament Injuries/veterinary , Cat Diseases/surgery , Cats , Joint Dislocations/veterinary , Retrospective Studies , Rupture/veterinary , Stifle/injuries , Stifle/surgery , Treatment Outcome
7.
Brain Connect ; 12(1): 26-40, 2022 02.
Article in English | MEDLINE | ID: mdl-34030485

ABSTRACT

Background: Alzheimer's disease (AD) is the most common form of dementia with genetic and environmental risk contributing to its development. Graph theoretical analyses of brain networks constructed from structural and functional magnetic resonance imaging (MRI) measurements have identified connectivity changes in AD and individuals with mild cognitive impairment. However, brain connectivity in asymptomatic individuals at risk of AD remains poorly understood. Methods: We analyzed diffusion-weighted MRI data from 161 asymptomatic individuals (38-71 years) from the Cardiff Ageing and Risk of Dementia Study (CARDS). We calculated white matter tracts and constructed whole-brain, default mode network (DMN) and visual structural brain networks that incorporate multiple structural metrics as edge weights. We then calculated the relationship of three AD risk factors, namely Apolipoprotein-E ɛ4 (APOE4) genotype, family history of dementia (FH), and central obesity (Waist-Hip-Ratio [WHR]), on graph theoretical measures and hubs. Results: We observed no risk-related differences in clustering coefficients, characteristic path lengths, eccentricity, diameter, and radius across the whole-brain, DMN or visual system. However, a hub in the right paracentral lobule was present in all the high-risk groups (FH, APOE4, obese), but absent in low-risk groups (no FH, APOE4-ve, healthy WHR). Discussion: We identified no risk-related effects on graph theoretical metrics in the structural brain networks of cognitively healthy individuals. However, high risk was associated with a hub in the right paracentral lobule, a medial fronto-parietal cortical area with motor and sensory functions. This finding is consistent with accumulating evidence for right parietal cortex contributions in AD. If this phenotype is shown to predict symptom development in longitudinal studies, it could be used as an early biomarker of AD. Impact statement Alzheimer's disease (AD) is a common form of dementia that to date has no cure. Identifying early biomarkers will aid the discovery and development of treatments that may slow AD progression in the future. In this article, we report that asymptomatic individuals at heightened risk of dementia due to their family history, Apolipoprotein-E ɛ4 genotype, and central adiposity have a hub in the right paracentral lobule, which is absent in low-risk groups. If this phenotype were to predict the development of symptoms in a longitudinal study of the same cohort, it could provide an early biomarker of disease progression.


Subject(s)
Alzheimer Disease , Alzheimer Disease/diagnostic imaging , Alzheimer Disease/genetics , Alzheimer Disease/pathology , Apolipoprotein E4/genetics , Brain , Humans , Longitudinal Studies , Magnetic Resonance Imaging/methods , Risk Factors
8.
Cereb Cortex ; 31(10): 4765-4780, 2021 08 26.
Article in English | MEDLINE | ID: mdl-34076234

ABSTRACT

The midcingulate cortex (MCC) is associated with cognition and emotion regulation. Structural and correlational functional evidence suggests that rather than being homogenous, the MCC may have dissociable functions that can be mapped onto distinct subregions. In this study, we use the marmoset monkey to causally investigate the contributions of two proposed subregions of the MCC: the anterior and posterior midcingulate cortices (aMCC and pMCC) to behavioral and cardiovascular correlates of threat processing relevant to anxiety disorders. Transient inactivation of the aMCC decreased anxiety-like responses to a postencounter distal threat, namely an unfamiliar human intruder, while inactivation of the pMCC showed a mild but opposing effect. Furthermore, although inactivation of neither MCC subregions had any effect on basal cardiovascular activity, aMCC inactivation blunted the expression of both cardiovascular and behavioral conditioned responses to a predictable proximal threat (a rubber snake) during the extinction in a Pavlovian conditioning task, with pMCC inactivation having again an opposing effect, but primarily on the behavioral response. These findings suggest that the MCC is indeed functionally heterogeneous with regards to its role in threat processing, with aMCC providing a marked facilitative contribution to the expression of the emotional response to both proximal and distal threat.


Subject(s)
Fear/physiology , Gyrus Cinguli/physiology , Animals , Anxiety/psychology , Behavior, Animal , Brain Mapping , Callithrix , Cardiovascular Physiological Phenomena , Conditioning, Classical , Emotions , Female , Gyrus Cinguli/diagnostic imaging , Humans , Magnetic Resonance Imaging , Male
9.
J Funct Morphol Kinesiol ; 6(1)2021 Feb 18.
Article in English | MEDLINE | ID: mdl-33670687

ABSTRACT

BACKGROUND: Eccentric resistance training (ERT) in youth is advocated for aiding performance and injury risk. However, research investigating the applied practices of ERT in youth is in its infancy. In this study, we surveyed the perceptions and practices of practitioners utilizing ERT in youth to provide an understanding of its current application in practice. METHODS: Sixty-four strength and conditioning coaches completed an online survey reporting their current use of ERT in youth using both open and closed questions. RESULTS: Coaches deemed the inclusion of ERT important in youth with its inclusion based upon factors such as maturation status, training age and strength levels. Coaches also displayed an awareness of the physiological responses to eccentric exercise in youth compared to adults. ERT was primarily used for injury prevention, with the majority of coaches using body-weight and tempo exercises. Furthermore, utilizing eccentric hamstrings exercises was reported as highly important. The frequency of ERT tended to increase in older age groups and coaches mainly prescribed self-selected rest intervals. Finally, the need for further research into the training guidelines of ERT in youth was highlighted, in which coaches require more information on how maturation influences training adaptations and the fatigue-recovery responses. CONCLUSION: Coaches emphasized the importance of including ERT for both performance and injury prevention factors in youth although further research is required to generate practical guidelines for coaches in order to support its inclusion within practice.

10.
Nat Commun ; 11(1): 5386, 2020 10 26.
Article in English | MEDLINE | ID: mdl-33106488

ABSTRACT

Stress-related disorders such as depression and anxiety are characterized by enhanced negative emotion and physiological dysfunction. Whilst elevated activity within area 25 of the subgenual anterior cingulate cortex (sgACC/25) has been implicated in these illnesses, it is unknown whether this over-activity is causal. By combining targeted intracerebral microinfusions with cardiovascular and behavioral monitoring in marmosets, we show that over-activation of sgACC/25 reduces vagal tone and heart rate variability, alters cortisol dynamics during stress and heightens reactivity to proximal and distal threat. 18F-FDG PET imaging shows these changes are accompanied by altered activity within a network of brain regions including the amygdala, hypothalamus and dorsolateral prefrontal cortex. Ketamine, shown to have rapid antidepressant effects, fails to reverse elevated arousal to distal threat contrary to the beneficial effects we have previously demonstrated on over-activation induced reward blunting, illustrating the symptom-specificity of its actions.


Subject(s)
Autonomic Pathways/physiology , Callithrix/psychology , Cardiovascular Physiological Phenomena , Gyrus Cinguli/physiology , Animals , Arousal , Behavior, Animal , Callithrix/physiology , Fear , Female , Gyrus Cinguli/diagnostic imaging , Heart Rate , Hydrocortisone/metabolism , Male , Positron Emission Tomography Computed Tomography
11.
BJGP Open ; 4(5)2020 Dec.
Article in English | MEDLINE | ID: mdl-33051222

ABSTRACT

BACKGROUND: Irritable bowel syndrome (IBS) is common and often negatively affects quality of life. Patients frequently perceive medical interventions as inadequate and seek support from other sources, including online discussion forums. AIM: To explore online discussion forum topics posted by people with IBS. DESIGN & SETTING: A qualitative study exploring three UK-based online discussion forums. METHOD: A scoping review identified UK-based discussion forums with high activity and frequent use, which did not require a password/registration to view posts (two IBS-specific and one general health forum). Internal search functions were used to identify and export relevant discussion threads relating to managing IBS. Inductive thematic analysis of exported discussions was undertaken. RESULTS: Analysis identified two main overarching themes from 122 relevant discussion threads: 1) sharing information and practical advice about lifestyle changes; and 2) receiving emotional support. The most prevalent topics were lifestyle changes, including diet, using oral preparations (for example, supplements or probiotics), and physical activity. Dietary changes were usually considered positive, and most hopeful for potentially alleviating symptoms. Emotional support was also regularly offered with expressions of empathy, kindness, and gratitude, and a sense of users feeling less alone. Some discussions raised concern around potentially inappropriate symptomatic reassurance, and negative or conflicting advice. CONCLUSION: Online forums seem, generally, to be a positive experience for those posting, but include potential risks of misinformation. Most posts focus on symptomatic relief through lifestyle change and/or emotional support. Clinicians could gain a better understanding of patients' ideas, concerns, and expectations of IBS diagnosis and management by asking about patient-acquired online forum information.

12.
Pancreatology ; 20(5): 976-983, 2020 Jul.
Article in English | MEDLINE | ID: mdl-32600854

ABSTRACT

BACKGROUND: Enhanced Recovery After Surgery (ERAS) for patients undergoing pancreatoduodenectomy is associated with reduced length of stay (LOS) and morbidity. However, external validating of the impact is difficult due to the multimodal aspects of ERAS. This study aimed to assess implementation of ERAS for pancreatoduodenectomy with a composite measure of multiple ideal outcome indicators defined as 'textbook outcome' (TBO). METHODS: In a tertiary referral center, 250 patients undergoing pancreatoduodenectomy were included in ERAS (May 2012-January 2017) and compared to a cohort of 125 patients undergoing traditional perioperative management (November 2009-April 2012). TBO was defined as proportion of patients without prolonged LOS, Clavien-Dindo ≥ III complications, postoperative pancreatic fistula, postpancreatectomy hemorrhage, bile leakage, readmissions or 30-day/in-hospital mortality. Additionally, overall treatment costs were calculated and compared using bootstrap independent t-test. RESULTS: The two cohorts were comparable in terms of demographic and surgical details. Implementation of ERAS was associated with reduced median LOS (10 days vs 13 days, p < 0.001) and comparable overall complication rate (62.0% vs 61.6%, p = 0.940) when compared to the traditional management group. In addition, a higher proportion of patients achieved TBO (56.4% vs 44.0%, p = 0.023) when treated according to ERAS principles. Furthermore, ERAS was associated with reduced mean total costs (£18132 vs £19385, p < 0.005). CONCLUSION: Implementation of ERAS for patients undergoing pancreatoduodenectomy is beneficial for both patients and hospitals. ERAS increased the proportion of patients achieving TBO and reduced overall costs. TBO is a potential measure for the evaluation of ERAS.


Subject(s)
Enhanced Recovery After Surgery , Pancreaticoduodenectomy/methods , Aged , Bile Duct Diseases/etiology , Cohort Studies , Cost Control , Female , Hospital Mortality , Humans , Length of Stay , Male , Middle Aged , Pancreatic Fistula/epidemiology , Pancreatic Fistula/therapy , Patient Readmission , Postoperative Complications/epidemiology , Postoperative Complications/therapy , Postoperative Hemorrhage/epidemiology , Postoperative Hemorrhage/therapy , Tertiary Care Centers , Treatment Outcome
13.
Proc Natl Acad Sci U S A ; 116(52): 26297-26304, 2019 Dec 26.
Article in English | MEDLINE | ID: mdl-31871181

ABSTRACT

The ventromedial prefrontal cortex (vmPFC) is consistently implicated in the cognitive and emotional symptoms of many psychiatric disorders, but the causal mechanisms of its involvement remain unknown. In part, this is because of the poor characterization of the disorders and their symptoms, and the focus of experimental studies in animals on subcortical (rather than cortical) dysregulation. Moreover, even in those experimental studies that have focused on the vmPFC, the preferred animal model for such research has been the rodent, in which there are marked differences in the organization of this region to that seen in humans, and thus the extent of functional homology is unclear. There is also a paucity of well-defined behavioral paradigms suitable for translating disorder-relevant findings across species. With these considerations in mind, we discuss the value of nonhuman primates (NHPs) in bridging the translational gap between human and rodent studies. We focus on recent investigations into the involvement in reward and threat processing of 2 major regions of the vmPFC, areas 25 and 32 in NHPs and their anatomical homologs, the infralimbic and prelimbic cortex, in rodents. We highlight potential similarities, but also differences between species, and consider them in light of the extent to which anatomical homology reflects functional homology, the expansion of the PFC in human and NHPs, and most importantly how they can guide future studies to improve the translatability of findings from preclinical animal studies into the clinic.

14.
Proc Natl Acad Sci U S A ; 116(29): 14761-14768, 2019 07 16.
Article in English | MEDLINE | ID: mdl-31266890

ABSTRACT

Genetic variation in the serotonin transporter gene (SLC6A4) is associated with vulnerability to affective disorders and pharmacotherapy efficacy. We recently identified sequence polymorphisms in the common marmoset SLC6A4 repeat region (AC/C/G and CT/T/C) associated with individual differences in anxiety-like trait, gene expression, and response to antidepressants. The mechanisms underlying the effects of these polymorphisms are unknown, but a key mediator of serotonin action is the serotonin 2A receptor (5HT2A). Thus, we correlated 5HT2A binding potential (BP) and RNA gene expression in 16 SLC6A4 genotyped marmosets with responsivity to 5HT2A antagonism during the human intruder test of anxiety. Voxel-based analysis and RNA measurements showed a reduction in 5HT2A BP and gene expression specifically in the right posterior insula of individuals homozygous for the anxiety-related variant AC/C/G. These same marmosets displayed an anxiogenic, dose-dependent response to the human intruder after 5HT2A pharmacological antagonism, while CT/T/C individuals showed no effect. A voxel-based correlation analysis, independent of SLC6A4 genotype, revealed that 5HT2A BP in the adjacent right anterior insula and insula proisocortex was negatively correlated with trait anxiety scores. Moreover, 5HT2A BP in both regions was a good predictor of the size and direction of the acute emotional response to the human intruder threat after 5HT2A antagonism. Our findings suggest that genetic variation in the SLC6A4 repeat region may contribute to the trait anxious phenotype via neurochemical changes in brain areas implicated in interoceptive and emotional processing, with a critical role for the right insula 5HT2A in the regulation of affective responses to threat.


Subject(s)
Anxiety/genetics , Behavior, Animal/physiology , Callithrix/physiology , Cerebral Cortex/pathology , Receptor, Serotonin, 5-HT2A/metabolism , Serotonin Plasma Membrane Transport Proteins/genetics , Animals , Anxiety/pathology , Anxiety/psychology , Behavior, Animal/drug effects , Female , Fluorobenzenes/administration & dosage , Genotype , Humans , Injections, Intramuscular , Male , Models, Animal , Piperidines/administration & dosage , Polymorphism, Genetic , Promoter Regions, Genetic/genetics , RNA/metabolism , Serotonin 5-HT2 Receptor Antagonists/administration & dosage , Serotonin Plasma Membrane Transport Proteins/metabolism , Stress, Psychological/genetics , Stress, Psychological/psychology
15.
Brain Sci ; 9(6)2019 Jun 03.
Article in English | MEDLINE | ID: mdl-31163643

ABSTRACT

Subcallosal area 25 is one of the least understood regions of the anterior cingulate cortex, but activity in this area is emerging as a crucial correlate of mood and affective disorder symptomatology. The cortical and subcortical connectivity of area 25 suggests it may act as an interface between the bioregulatory and emotional states that are aberrant in disorders such as depression. However, evidence for such a role is limited because of uncertainty over the functional homologue of area 25 in rodents, which hinders cross-species translation. This emphasizes the need for causal manipulations in monkeys in which area 25, and the prefrontal and cingulate regions in which it is embedded, resemble those of humans more than rodents. In this review, we consider physiological and behavioral evidence from non-pathological and pathological studies in humans and from manipulations of area 25 in monkeys and its putative homologue, the infralimbic cortex (IL), in rodents. We highlight the similarities between area 25 function in monkeys and IL function in rodents with respect to the regulation of reward-driven responses, but also the apparent inconsistencies in the regulation of threat responses, not only between the rodent and monkey literatures, but also within the rodent literature. Overall, we provide evidence for a causal role of area 25 in both the enhanced negative affect and decreased positive affect that is characteristic of affective disorders, and the cardiovascular and endocrine perturbations that accompany these mood changes. We end with a brief consideration of how future studies should be tailored to best translate these findings into the clinic.

16.
J Neurosci ; 39(16): 3094-3107, 2019 04 17.
Article in English | MEDLINE | ID: mdl-30718320

ABSTRACT

High-trait anxiety is a risk factor for the development of affective disorders and has been associated with decreased cardiovascular and behavioral responsivity to acute stressors in humans that may increase the risk of developing cardiovascular disease. Although human neuroimaging studies of high-trait anxiety reveals dysregulation in primate cingulate areas 25 and 32 and the anterior hippocampus (aHipp) and rodent studies reveal the importance of aHipp glutamatergic hypofunction, the causal involvement of aHipp glutamate and its interaction with these areas in the primate brain is unknown. Accordingly, we correlated marmoset trait anxiety scores to their postmortem aHipp glutamate levels and showed that low glutamate in the right aHipp is associated with high-trait anxiety in marmosets. Moreover, pharmacologically increasing aHipp glutamate reduced anxiety levels in highly anxious marmosets in two uncertainty-based tests of anxiety: exposure to a human intruder with uncertain intent and unpredictable loud noise. In the human intruder test, increasing aHipp glutamate decreased anxiety by increasing approach to the intruder. In the unpredictable threat test, animals showed blunted behavioral and cardiovascular responsivity after control infusions, which was normalized by increasing aHipp glutamate. However, this aHipp-mediated anxiolytic effect was blocked by simultaneous pharmacological inactivation of area 25, but not area 32, areas which when inactivated independently reduced and had no effect on anxiety, respectively. These findings provide causal evidence in male and female primates that aHipp glutamatergic hypofunction and its regulation by area 25 contribute to the behavioral and cardiovascular symptoms of endogenous high-trait anxiety.SIGNIFICANCE STATEMENT High-trait anxiety predisposes sufferers to the development of anxiety and depression. Although neuroimaging of these disorders and rodent modeling implicate dysregulation in hippocampal glutamate and the subgenual/perigenual cingulate cortices (areas 25/32), the causal involvement of these structures in endogenous high-trait anxiety and their interaction are unknown. Here, we demonstrate that increased trait anxiety in marmoset monkeys correlates with reduced hippocampal glutamate and that increasing hippocampal glutamate release in high-trait-anxious monkeys normalizes the aberrant behavioral and cardiovascular responsivity to potential threats. This normalization was blocked by simultaneous inactivation of area 25, but not area 32. These findings provide casual evidence in primates that hippocampal glutamatergic hypofunction regulates endogenous high-trait anxiety and the hippocampal-area 25 circuit is a potential therapeutic target.


Subject(s)
Anxiety/metabolism , Behavior, Animal/physiology , Glutamic Acid/metabolism , Heart Rate/physiology , Hippocampus/metabolism , Amino Acids/pharmacology , Animals , Behavior, Animal/drug effects , Benzylamines/pharmacology , Callithrix , Excitatory Amino Acid Antagonists/pharmacology , Female , GABA-A Receptor Antagonists/pharmacology , Heart Rate/drug effects , Hippocampus/drug effects , Male , Phosphinic Acids/pharmacology , Xanthenes/pharmacology
17.
Cereb Cortex ; 29(11): 4818-4830, 2019 12 17.
Article in English | MEDLINE | ID: mdl-30796800

ABSTRACT

Affective disorders are associated with increased sensitivity to negative feedback that influences approach-avoidance decision making. Although neuroimaging studies of these disorders reveal dysregulation in primate cingulate areas 25 and 32 and the anterior hippocampus (aHipp), the causal involvement of these structures and their interaction in the primate brain is unknown. We therefore investigated the effects of localized pharmacological manipulations of areas 25 and 32 and/or the aHipp of the marmoset monkey on performance of an anxiolytic-sensitive instrumental decision-making task in which an approach-avoidance conflict is created by pairing a response with reward and punishment. During control infusions animals avoided punishment, but this bias was reduced by increasing glutamate release within the aHipp or area 32, and inactivation or 5-HT1a antagonism within area 25. Conversely, increasing glutamate release in area 25 enhanced punishment avoidance but, in contrast to previous reports, area 32 and aHipp inactivations had no effect. Simultaneous inactivation or 5-HT1a antagonism within area 25, but not area 32, abolished the reduced punishment avoidance seen after increasing aHipp glutamate. Besides providing causal evidence that these primate areas differentially regulate negative feedback sensitivity, this study links the decision-making deficits in affective disorders to aberrant aHipp-area 25 circuit activity.


Subject(s)
Avoidance Learning/physiology , Choice Behavior/physiology , Decision Making/physiology , Hippocampus/physiology , Prefrontal Cortex/physiology , Punishment , Reward , Animals , Callithrix , Conflict, Psychological , Female , Glutamic Acid/physiology , Male
18.
Neuron ; 101(2): 307-320.e6, 2019 01 16.
Article in English | MEDLINE | ID: mdl-30528065

ABSTRACT

Anhedonia is a core symptom of depression, but the underlying neurobiological mechanisms are unknown. Correlative neuroimaging studies implicate dysfunction within ventromedial prefrontal cortex, but the causal roles of specific subregions remain unidentified. We addressed these issues by combining intracerebral microinfusions with cardiovascular and behavioral monitoring in marmoset monkeys to show that over-activation of primate subgenual anterior cingulate cortex (sgACC, area 25) blunts appetitive anticipatory, but not consummatory, arousal, whereas manipulations of adjacent perigenual ACC (pgACC, area 32) have no effect. sgACC/25 over-activation also reduces the willingness to work for reward. 18F-FDG PET imaging reveals over-activation induced metabolic changes in circuits involved in reward processing and interoception. Ketamine treatment ameliorates the blunted anticipatory arousal and reverses associated metabolic changes. These results demonstrate a causal role for primate sgACC/25 over-activity in selective aspects of impaired reward processing translationally relevant to anhedonia, and ketamine's modulation of an affective network to exert its action.


Subject(s)
Anhedonia/physiology , Conditioning, Classical/physiology , Gyrus Cinguli/physiology , Reward , Anhedonia/drug effects , Animals , Blood Pressure/physiology , Callithrix , Citalopram/pharmacology , Discrimination, Psychological , Disease Models, Animal , Excitatory Amino Acid Antagonists/pharmacology , Female , Fluorodeoxyglucose F18/pharmacokinetics , Food Preferences/drug effects , Food Preferences/physiology , Gyrus Cinguli/diagnostic imaging , Humans , Ketamine/pharmacology , Locomotion/physiology , Male , Proto-Oncogene Proteins c-fos/metabolism , Selective Serotonin Reuptake Inhibitors/pharmacology , Stress, Psychological/psychology , Sucrose/administration & dosage
19.
Am J Pathol ; 189(3): 632-647, 2019 03.
Article in English | MEDLINE | ID: mdl-30553836

ABSTRACT

Osteoarthritis (OA) is a common degenerative joint disease, characterized by cartilage loss and subchondral bone remodeling in response to abnormal mechanical load. Heparan sulfate (HS) proteoglycans bind to many proteins that regulate cartilage homeostasis, including growth factors, morphogens, proteases, and their inhibitors, and modulate their localization, retention, and biological activity. Changes in HS expression and structure may thus have important consequences for joint health. We analyzed normal and osteoarthritic human knee cartilage, and found HS biosynthesis was markedly disrupted in OA, with 45% of the 38 genes analyzed differentially regulated in diseased cartilage. The expression of several HS core proteins, biosynthesis, and modification enzymes was increased in OA cartilage, whereas the expression of the HS proteoglycans syndecan 4 and betaglycan was reduced. The structure of HS was also altered, with increased levels of 6-O-sulfation in osteoarthritic samples, which correlated with increased expression of HS6ST1, a 6-O-sulfotransferase, and GLCE, an epimerase that promotes 6-O-sulfation. siRNA silencing of HS6ST1 expression in primary OA chondrocytes inhibited extracellular signal-regulated kinase phosphorylation in response to fibroblast growth factor 2, showing that changes in 6-O-sulfation impact a key cartilage signaling pathway. Given the broad range of homeostatic and repair pathways that HS regulates, these changes in proteoglycan expression and HS structure are likely to have significant effects on joint health and progression of OA.


Subject(s)
Cartilage/metabolism , Chondrocytes/metabolism , Gene Expression Regulation , Knee Joint/metabolism , Osteoarthritis, Knee/metabolism , Syndecan-4/biosynthesis , Cartilage/pathology , Chondrocytes/pathology , Female , Fibroblast Growth Factor 2/metabolism , Humans , Knee Joint/pathology , MAP Kinase Signaling System , Male , Osteoarthritis, Knee/pathology , Sulfotransferases/biosynthesis
20.
Soc Nat Resour ; 30(2): 129-144, 2017.
Article in English | MEDLINE | ID: mdl-29104368

ABSTRACT

Culture plays an important role in communities' abilities to adapt to environmental change and crises. The emerging field of resilience thinking has made several efforts to better integrate social and cultural factors into the systems-level approach to understanding socialecological resilience. However, attempts to integrate culture into structural models often fail to account for the agentic processes that influence recovery at the individual and community levels, overshadowing the potential for agency and variation in community response. Using empirical data on the 2010 BP oil spill's impact on a small, natural resource-dependent community, we propose an alternative approach emphasizing culture's ability to operate as a resource that contributes to social, or community, resilience. We refer to this more explicit articulation of culture's role in resilience as cultural resilience. Our findings reveal that not all cultural resources that define resilience in reference to certain disasters provided successful mitigation, adaptation, or recovery from the BP spill.

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