Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 76
Filtrar
1.
Nat Neurosci ; 27(4): 782-792, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38491324

RESUMO

The interplay between excitation and inhibition determines the fidelity of cortical representations. The receptive fields of excitatory neurons are often finely tuned to encoded features, but the principles governing the tuning of inhibitory neurons remain elusive. In this study, we recorded populations of neurons in the mouse postsubiculum (PoSub), where the majority of excitatory neurons are head-direction (HD) cells. We show that the tuning of fast-spiking (FS) cells, the largest class of cortical inhibitory neurons, was broad and frequently radially symmetrical. By decomposing tuning curves using the Fourier transform, we identified an equivalence in tuning between PoSub-FS and PoSub-HD cell populations. Furthermore, recordings, optogenetic manipulations of upstream thalamic populations and computational modeling provide evidence that the tuning of PoSub-FS cells has a local origin. These findings support the notion that the equivalence of neuronal tuning between excitatory and inhibitory cell populations is an intrinsic property of local cortical networks.


Assuntos
Neurônios , Tálamo , Camundongos , Animais , Neurônios/fisiologia , Inibição Neural/fisiologia , Potenciais de Ação/fisiologia
2.
Pilot Feasibility Stud ; 9(1): 170, 2023 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-37798752

RESUMO

BACKGROUND: The NHS Talking Therapies for Anxiety and Depression programme ('TTad'; formerly Improving Access to Psychological Therapies 'IAPT') delivers high-intensity cognitive behavioural therapy (CBT) to over 200,000 individuals each year for common mental health problems like depression and anxiety. More than half of these individuals experience comorbid personality difficulties, who show poorer treatment outcomes. TTad therapists report feeling unskilled to work with clients with personality difficulties, and enhancing the training of TTad therapists may lead to improved treatment outcomes for individuals presenting with secondary personality difficulties alongside depression and anxiety. METHODS: This is a pre-post non-randomised mixed-method feasibility study, exploring the feasibility and acceptability of a 1-day training workshop for high-intensity (HI) CBT therapists. The workshop is focused on understanding and assessing personality difficulties and adapting HICBT treatments for anxiety and depression to accommodate client needs. The feasibility and acceptability of the workshop and the evaluation procedures will be investigated. It will be examined to what extent the workshop provision leads to improvements in therapist skills and confidence and explored to what extent the training has the potential to enhance clinical outcomes for this client group. DISCUSSION: This feasibility study will provide data on the acceptability and feasibility of delivering brief therapist training to adapt usual HICBT to optimise care for individuals with secondary personality difficulties seeking treatment in TTad services for a primary problem of depression and/or anxiety. The study will also evaluate proof of concept that such an approach has the potential to improve clinical outcomes for those with secondary personality difficulties and report any possible harms identified. The study will inform the design of a future randomised controlled trial designed to test the effectiveness and cost-effectiveness of the training. TRIAL REGISTRATION: ISRCTN81104604 . Submitted on 6th June 2022. Registration date: 3rd January 2023.

3.
J Acad Ophthalmol (2017) ; 15(2): e184-e187, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37701862

RESUMO

Introduction: This study aims to evaluate the performance of ChatGPT-4, an advanced artificial intelligence (AI) language model, on the Ophthalmology Knowledge Assessment Program (OKAP) examination compared to its predecessor, ChatGPT-3.5. Methods: Both models were tested on 180 OKAP practice questions covering various ophthalmology subject categories. Results: ChatGPT-4 significantly outperformed ChatGPT-3.5 (81% vs. 57%; p <0.001), indicating improvements in medical knowledge assessment. Discussion: The superior performance of ChatGPT-4 suggests potential applicability in ophthalmologic education and clinical decision support systems. Future research should focus on refining AI models, ensuring a balanced representation of fundamental and specialized knowledge, and determining the optimal method of integrating AI into medical education and practice.

4.
Adv Drug Deliv Rev ; 198: 114869, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37172782

RESUMO

Ocular immune privilege is a phenomenon described by Peter Medawar in relation to the indefinite survival of the placement of foreign tissue grafts into the eye. Several mechanisms have been described that contribute to ocular immune privilege, such as a blood-ocular barrier and lack of lymphatics in the eye, the production of immune-suppressing molecules inside the ocular microenvironment, and the induction of systemic regulatory immunity against antigens found in the eye. Because ocular immune privilege is not absolute, failure of it can result in uveitis. Uveitis is a group of inflammatory disorders that can lead to vision loss if not treated properly. The current uveitis treatments involve the use of immunosuppressive and anti-inflammatory medications. Researching mechanisms of ocular immune privilege and the development of novel treatments for uveitis is ongoing. This review discusses mechanisms of ocular immune privilege, followed by an overview of uveitis treatments and ongoing clinical trials.


Assuntos
Olho , Uveíte , Humanos , Uveíte/tratamento farmacológico , Antígenos
5.
Hippocampus ; 33(7): 811-829, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-36808771

RESUMO

A fundamental property of place cells in the hippocampus is the anchoring of their firing fields to salient landmarks within the environment. However, it is unclear how such information reaches the hippocampus. In the current experiment, we tested the hypothesis that the stimulus control exerted by distal visual landmarks requires input from the medial entorhinal cortex (MEC). Place cells were recorded from mice with ibotenic acid lesions of the MEC (n = 7) and from sham-lesioned mice (n = 6) following 90° rotations of either distal landmarks or proximal cues in a cue- controlled environment. We found that lesions of the MEC impaired the anchoring of place fields to distal landmarks, but not proximal cues. We also observed that, relative to sham-lesioned mice, place cells in animals with MEC lesions exhibited significantly reduced spatial information and increased sparsity. These results support the view that distal landmark information reaches the hippocampus via the MEC, but that proximal cue information can do so via an alternative neural pathway.


Assuntos
Córtex Entorrinal , Células de Lugar , Camundongos , Animais , Córtex Entorrinal/patologia , Hipocampo/patologia , Vias Neurais , Sinais (Psicologia)
6.
Mol Autism ; 13(1): 49, 2022 12 20.
Artigo em Inglês | MEDLINE | ID: mdl-36536454

RESUMO

BACKGROUND: Fragile X syndrome (FXS) is a common single gene cause of intellectual disability and autism spectrum disorder. Cognitive inflexibility is one of the hallmarks of FXS with affected individuals showing extreme difficulty adapting to novel or complex situations. To explore the neural correlates of this cognitive inflexibility, we used a rat model of FXS (Fmr1-/y). METHODS: We recorded from the CA1 in Fmr1-/y and WT littermates over six 10-min exploration sessions in a novel environment-three sessions per day (ITI 10 min). Our recordings yielded 288 and 246 putative pyramidal cells from 7 WT and 7 Fmr1-/y rats, respectively. RESULTS: On the first day of exploration of a novel environment, the firing rate and spatial tuning of CA1 pyramidal neurons was similar between wild-type (WT) and Fmr1-/y rats. However, while CA1 pyramidal neurons from WT rats showed experience-dependent changes in firing and spatial tuning between the first and second day of exposure to the environment, these changes were decreased or absent in CA1 neurons of Fmr1-/y rats. These findings were consistent with increased excitability of Fmr1-/y CA1 neurons in ex vivo hippocampal slices, which correlated with reduced synaptic inputs from the medial entorhinal cortex. Lastly, activity patterns of CA1 pyramidal neurons were dis-coordinated with respect to hippocampal oscillatory activity in Fmr1-/y rats. LIMITATIONS: It is still unclear how the observed circuit function abnormalities give rise to behavioural deficits in Fmr1-/y rats. Future experiments will focus on this connection as well as the contribution of other neuronal cell types in the hippocampal circuit pathophysiology associated with the loss of FMRP. It would also be interesting to see if hippocampal circuit deficits converge with those seen in other rodent models of intellectual disability. CONCLUSIONS: In conclusion, we found that hippocampal place cells from Fmr1-/y rats show similar spatial firing properties as those from WT rats but do not show the same experience-dependent increase in spatial specificity or the experience-dependent changes in network coordination. Our findings offer support to a network-level origin of cognitive deficits in FXS.


Assuntos
Síndrome do Cromossomo X Frágil , Animais , Ratos , Modelos Animais de Doenças , Proteína do X Frágil da Deficiência Intelectual/genética , Síndrome do Cromossomo X Frágil/genética , Hipocampo/metabolismo
7.
Front Behav Neurosci ; 16: 969871, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36523755

RESUMO

Introduction: Episodic memory formation requires the binding of multiple associations to a coherent episodic representation, with rich detail of times, places, and contextual information. During postnatal development, the ability to recall episodic memories emerges later than other types of memory such as object recognition. However, the precise developmental trajectory of episodic memory, from weaning to adulthood has not yet been established in rats. Spontaneous object exploration tasks do not require training, and allow repeated testing of subjects, provided novel objects are used on each trial. Therefore, these tasks are ideally suited for the study of the ontogeny of episodic memory and its constituents (e.g., object, spatial, and contextual memory). Methods: In the present study, we used four spontaneous short-term object exploration tasks over two days: object (OR), object-context (OCR), object-place (OPR), and object-place-context (OPCR) recognition to characterise the ontogeny of episodic-like memory and its components in three commonly used outbred rat strains (Lister Hooded, Long Evans Hooded, and Sprague Dawley). Results: In longitudinal studies starting at 3-4 weeks of age, we observed that short term memory for objects was already present at the earliest time point we tested, indicating that it is established before the end of the third week of life (consistent with several other reports). Object-context memory developed during the fifth week of life, while both object-in-place and the episodic-like object-place-context memory developed around the seventh postnatal week. To control for the effects of previous experience in the development of associative memory, we confirmed these developmental trajectories using a cross-sectional protocol. Discussion: Our work provides robust evidence for different developmental trajectories of recognition memory in rats depending on the content and/or complexity of the associations and emphasises the utility of spontaneous object exploration tasks to assess the ontogeny of memory systems with high temporal resolution.

8.
Confl Health ; 16(1): 56, 2022 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-36352443

RESUMO

BACKGROUND: Understanding and improving access to essential services in (post)-conflict settings requires paying particular attention to the actors who occupy the space left 'empty' by weak or deficient State institutions. Religious institutions often play a fundamental role among these actors and typically benefit from high trust capital, a rare resource in so-called 'fragile' states. While there is a literature looking at the role faith organisations play to mobilise and sensitise communities during emergencies, our focus is on a different dimension: the reconfiguration of the relationship between religion and health authorities impelled by health crises. METHODS: We analyse observations, interviews, and focus group discussions with 21 leaders from eight different religious groups in Ituri province in 2020-2021. RESULTS: Faith institutions handled the Covid-19 lockdown period by using and redeploying structures at the grassroots level but also by responding to health authorities' call for support. New actors usually not associated with the health system, such as revivalist churches, became involved. The interviewed religious leaders, especially those whose congregations were not previously involved in healthcare provision, felt that they were doing a favour to the State and the health authorities by engaging in community-level awareness-raising, but also, crucially, by 'depoliticising' Covid-19 through their public commitment against Covid-19 and work with the authorities in a context where the public response to epidemics has been highly contentious in recent years (particularly during the Ebola outbreak). The closure of places of worship during the lockdown shocked all faith leaders but, ultimately, most were inclined to follow and support health authorities. Such experience was, however, often one of frustration and of feeling unheard. CONCLUSION: In the short run, depoliticization may help address health emergencies, but in the longer run and in the absence of a credible space for discussion, it may affect the constructive criticism of health system responses and health system strengthening. The faith leaders are putting forward the desire for a relationship that is not just subordination of the religious to the imperatives of health care but a dialogue that allows the experiences of the faithful in conflict zones to be brought to the fore.

9.
Brain Commun ; 4(6): fcac263, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36349120

RESUMO

Mutations in the SYNGAP1 gene are one of the common predictors of neurodevelopmental disorders, commonly resulting in individuals developing autism, intellectual disability, epilepsy, and sleep deficits. EEG recordings in neurodevelopmental disorders show potential to identify clinically translatable biomarkers to both diagnose and track the progress of novel therapeutic strategies, as well as providing insight into underlying pathological mechanisms. In a rat model of SYNGAP1 haploinsufficiency in which the exons encoding the calcium/lipid binding and GTPase-activating protein domains have been deleted (Syngap+/Δ-GAP ), we analysed the duration and occurrence of wake, non-rapid eye movement and rapid eye movement brain states during 6 h multi-electrode EEG recordings. We find that although Syngap+/Δ-GAP animals spend an equivalent percent time in wake and sleep states, they have an abnormal brain state distribution as the number of wake and non-rapid eye movement bouts are reduced and there is an increase in the average duration of both wake and non-rapid eye movement epochs. We perform connectivity analysis by calculating the average imaginary coherence between electrode pairs at varying distance thresholds during these states. In group averages from pairs of electrodes at short distances from each other, a clear reduction in connectivity during non-rapid eye movement is present between 11.5 Hz and 29.5 Hz, a frequency range that overlaps with sleep spindles, oscillatory phenomena thought to be important for normal brain function and memory consolidation. Sleep abnormalities were mostly uncorrelated to the electrophysiological signature of absence seizures, spike and wave discharges, as was the imaginary coherence deficit. Sleep spindles occurrence, amplitude, power and spread across multiple electrodes were not reduced in Syngap+/Δ-GAP rats, with only a small decrease in duration detected. Nonetheless, by analysing the dynamic imaginary coherence during sleep spindles, we found a reduction in high-connectivity instances between short-distance electrode pairs. Finally comparing the dynamic imaginary coherence during sleep spindles between individual electrode pairs, we identified a group of channels over the right somatosensory, association and visual cortices that have a significant reduction in connectivity during sleep spindles in mutant animals. This matched a significant reduction in connectivity during spindles when averaged regional comparisons were made. These data suggest that Syngap+/Δ-GAP rats have altered brain state dynamics and EEG connectivity, which may have clinical relevance for SYNGAP1 haploinsufficiency in humans.

10.
Curr Biol ; 32(20): 4451-4464.e7, 2022 10 24.
Artigo em Inglês | MEDLINE | ID: mdl-36099915

RESUMO

Neurons in the retrohippocampal cortices play crucial roles in spatial memory. Many retrohippocampal neurons have firing fields that are selectively active at specific locations, with memory for rewarded locations associated with reorganization of these firing fields. Whether this is the sole strategy for representing spatial memories is unclear. Here, we demonstrate that during a spatial memory task retrohippocampal neurons encode location through ramping activity that extends across segments of a linear track approaching and following a reward, with the rewarded location represented by offsets or switches in the slope of the ramping activity. Ramping representations could be maintained independently of trial outcome and cues marking the reward location, indicating that they result from recall of the track structure. When recorded in an open arena, neurons that generated ramping activity during the spatial memory task were more numerous than grid or border cells, with a majority showing spatial firing that did not meet criteria for classification as grid or border representations. Encoding of rewarded locations through offsets and switches in the slope of ramping activity also emerged in recurrent neural network models trained to solve a similar spatial memory task. Impaired performance of model networks following disruption of outputs from ramping neurons is consistent with this coding strategy supporting navigation to recalled locations of behavioral significance. Our results suggest that encoding of learned spaces by retrohippocampal networks employs both discrete firing fields and continuous ramping representations. We hypothesize that retrohippocampal ramping activity mediates readout of learned models for goal-directed navigation.


Assuntos
Hipocampo , Neurônios , Hipocampo/fisiologia , Neurônios/fisiologia , Córtex Cerebral , Memória Espacial , Recompensa
11.
Pharmaceutics ; 14(9)2022 09 13.
Artigo em Inglês | MEDLINE | ID: mdl-36145679

RESUMO

Ocular drug delivery has been significantly advanced for not only pharmaceutical compounds, such as steroids, nonsteroidal anti-inflammatory drugs, immune modulators, antibiotics, and so forth, but also for the rapidly progressed gene therapy products. For conventional non-gene therapy drugs, appropriate surgical approaches and releasing systems are the main deliberation to achieve adequate treatment outcomes, whereas the scope of "drug delivery" for gene therapy drugs further expands to transgene construct optimization, vector selection, and vector engineering. The eye is the particularly well-suited organ as the gene therapy target, owing to multiple advantages. In this review, we will delve into three main aspects of ocular drug delivery for both conventional drugs and adeno-associated virus (AAV)-based gene therapy products: (1) the development of AAV vector systems for ocular gene therapy, (2) the innovative carriers of medication, and (3) administration routes progression.

12.
Front Public Health ; 10: 916062, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36176526

RESUMO

Purpose: To understand challenges faced by faith leaders in the Democratic Republic of Congo (DRC) in engaging with current public health strategies for the COVID-19 pandemic; to explain why long-standing collaborations between government, faith-based health services and leaders of faith communities had little impact; to identify novel approaches to develop effective messaging that resonates with local communities. Methods: A qualitative participatory research design, using a workshop methodology was deployed to seek opinions of an invited group of faith leaders in the DRC provinces of Ituri and Nord-Kivu. A topic guide was developed from data gathered in prior qualitative interviews of faith leaders and members. Topics were addressed at a small workshop discussion. Emerging themes were identified. Findings: Local faith leaders described how misinterpretation and misinformation about COVID-19 and public health measures led to public confusion. Leaders described a lack of capacity to do what was being asked by government authorities with COVID-19 measures. Leaders' knowledge of faith communities' concerns was not sought. Leaders regretted having no training to formulate health messages. Faith leaders wanted to co-create public health messages with health officials for more effective health messaging. Conclusion: Public trust in faith leaders is crucial in health emergencies. The initial request by government authorities for faith leaders to deliver set health messages rather than co-develop and design messages appropriate for their congregations resulted in faith communities not understanding health messages. Delivering public health messages using language familiar to faith communities could help to ensure more effective public health communication and counter misinformation.


Assuntos
COVID-19 , Saúde Pública , COVID-19/epidemiologia , COVID-19/prevenção & controle , República Democrática do Congo , Humanos , Pandemias , Pesquisa Qualitativa
13.
Mol Autism ; 13(1): 34, 2022 07 18.
Artigo em Inglês | MEDLINE | ID: mdl-35850732

RESUMO

BACKGROUND: Mutations in the postsynaptic transmembrane protein neuroligin-3 are highly correlative with autism spectrum disorders (ASDs) and intellectual disabilities (IDs). Fear learning is well studied in models of these disorders, however differences in fear response behaviours are often overlooked. We aim to examine fear behaviour and its cellular underpinnings in a rat model of ASD/ID lacking Nlgn3. METHODS: This study uses a range of behavioural tests to understand differences in fear response behaviour in Nlgn3-/y rats. Following this, we examined the physiological underpinnings of this in neurons of the periaqueductal grey (PAG), a midbrain area involved in flight-or-freeze responses. We used whole-cell patch-clamp recordings from ex vivo PAG slices, in addition to in vivo local-field potential recordings and electrical stimulation of the PAG in wildtype and Nlgn3-/y rats. We analysed behavioural data with two- and three-way ANOVAS and electrophysiological data with generalised linear mixed modelling (GLMM). RESULTS: We observed that, unlike the wildtype, Nlgn3-/y rats are more likely to response with flight rather than freezing in threatening situations. Electrophysiological findings were in agreement with these behavioural outcomes. We found in ex vivo slices from Nlgn3-/y rats that neurons in dorsal PAG (dPAG) showed intrinsic hyperexcitability compared to wildtype. Similarly, stimulating dPAG in vivo revealed that lower magnitudes sufficed to evoke flight behaviour in Nlgn3-/y than wildtype rats, indicating the functional impact of the increased cellular excitability. LIMITATIONS: Our findings do not examine what specific cell type in the PAG is likely responsible for these phenotypes. Furthermore, we have focussed on phenotypes in young adult animals, whilst the human condition associated with NLGN3 mutations appears during the first few years of life. CONCLUSIONS: We describe altered fear responses in Nlgn3-/y rats and provide evidence that this is the result of a circuit bias that predisposes flight over freeze responses. Additionally, we demonstrate the first link between PAG dysfunction and ASD/ID. This study provides new insight into potential pathophysiologies leading to anxiety disorders and changes to fear responses in individuals with ASD.


Assuntos
Transtorno Autístico , Animais , Transtorno Autístico/metabolismo , Medo/fisiologia , Congelamento , Humanos , Neurônios/fisiologia , Substância Cinzenta Periaquedutal/metabolismo , Ratos
14.
Artigo em Inglês | MEDLINE | ID: mdl-35682476

RESUMO

The COVID-19 pandemic and its profound global effects may be changing the way we think about illness. In summer 2020, 120 American adults were asked to diagnose symptoms of COVID-19, a cold, and cancer, and to answer questions related to the diagnosis, treatment, prevention, time-course, and transmission of each disease. Results showed that participants were more likely to correctly diagnose COVID-19 (91% accuracy) compared to a cold (58% accuracy) or cancer (52% accuracy). We also found that 7% of participants misdiagnosed cold symptoms as COVID-19, and, interestingly, over twice as many participants (16%) misdiagnosed symptoms of cancer as COVID-19. Our findings suggest a distinct mental model for COVID-19 compared to other illnesses. Further, the prevalence of COVID-19 in everyday discourse-especially early in the pandemic-may lead to biased responding, similar to errors in medical diagnosis that result from physicians' expertise. We also discuss how the focus of public-health messaging on prevention of COVID-19 might contribute to participants' mental models.


Assuntos
COVID-19 , Adulto , COVID-19/epidemiologia , Humanos , Modelos Psicológicos , Pandemias/prevenção & controle , Prevalência , SARS-CoV-2 , Estados Unidos
15.
J Phys Chem B ; 126(11): 2285-2298, 2022 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-35290739

RESUMO

Board-shaped polymers form sanidic mesophases: assemblies of parallel lamellae of stacked polymer backbones separated by disordered side chains. Sanidics vary significantly with respect to polymer order inside their lamellae, making them "stepping stones" toward the crystalline state. Therefore, they are potentially interesting for studying crystallization and technological applications. Building on earlier mesoscopic models of the most disordered sanidics Σd, we focus on the other extreme, near-crystalline order, and develop a generic model that captures a highly ordered Σr mesophase. Polymers are described by generic hindered-rotation chains. Anisotropic nonbonded potentials, with strengths comparable to the thermal energy, mimic board-like monomer shapes. Lamellae equilibrated with Monte Carlo simulations, for a broad range of model parameters, have intralamellar order typical for Σr mesophases: periodically stacked polymers that are mutually registered along their backbones. Our mesophase shows registration on both monomer and chain levels. We calculate scattering patterns and compare with data published for highly ordered sanidic mesophases of two different polymers: polyesters and polypeptoids. Most of the generic structural features that were identified in these experiments are present in our model. However, our mesophase has correlations between chains located in different lamellae and is therefore closer to the crystalline state than the experimental samples.

16.
Cochrane Database Syst Rev ; 2: CD005398, 2022 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-35129214

RESUMO

BACKGROUND: Seizures after stroke are an important clinical problem and may result in poor outcomes. The indications of antiepileptic drugs (AEDs) for seizure prophylaxis after stroke remain unclear. This is an updated version of the Cochrane Review previously published in 2014. OBJECTIVES: To assess the effects of AEDs for the primary and secondary prevention of seizures after stroke. For primary prevention, we aimed to assess whether AEDs reduce the likelihood of seizures in people who have a stroke but do not have a seizure. For secondary prevention, we aimed to assess whether AEDs reduce the likelihood of further seizures in people who have a stroke and at least one post-stroke seizure. SEARCH METHODS: We searched the following databases on 9 March 2021: Cochrane Register of Studies (CRS Web), MEDLINE (Ovid, 1946 to March 08, 2021). CRS Web includes randomised or quasi-randomised controlled trials from PubMed, Embase, ClinicalTrials.gov, the World Health Organisation International Clinical Trials Registry Platform (ICTRP), the Cochrane Central Register of Controlled Trials (CENTRAL), and the Specialised Registers of Cochrane Review Groups including Epilepsy and Stroke. We also checked the reference lists of articles retrieved from these searches. SELECTION CRITERIA: We selected randomised and quasi-randomised controlled studies that recruited participants with a clinical diagnosis of stroke, either ischaemic or haemorrhagic. We excluded studies that only recruited participants with subarachnoid haemorrhage, subdural haemorrhage, extradural haemorrhage, or other non-stroke diagnoses such as tumour- or infection-related infarction or haemorrhage. We also excluded studies that recruited only participants who had undergone neurosurgery. We included participants of all ages suffering any seizure type who were assigned to AEDs or placebo groups. DATA COLLECTION AND ANALYSIS: In accordance with standard methodological procedures expected by The Cochrane Collaboration, two review authors independently assessed trials for inclusion before evaluating trial risk of bias and extracting relevant data. The primary outcome assessed was the proportion of participants who experienced seizures in the follow-up period. We presented results as summary risk ratios (RRs) with 95% confidence intervals (CIs) for dichotomous outcomes and mean differences (MDs) with 95% CIs for continuous outcomes. Where we had sufficient data, we calculated random-effects (Mantel-Haenszel) meta-analyses for dichotomous outcomes; otherwise, we reported results narratively. We used the I2 statistic to analyse statistical heterogeneity. We planned to use funnel plots to assess publication bias in meta-analyses with at least 10 included studies. We used the GRADE approach to assess the certainty of the evidence. MAIN RESULTS: Two studies with a total of 856 subjects were included. AEDs were not shown to be effective in primary prophylaxis of post-stroke seizure (RR 0.65, 95% CI 0.34 to 1.26; 2 studies, 856 participants; moderate-certainty evidence). The first study was a randomised double-blind study comparing valproic acid with placebo for primary seizure prevention up to one year after stroke. The study included 72 adults with intracerebral haemorrhage. There was no difference in the risk of post-stroke seizures (RR 0.88, 95% CI 0.35 to 2.16) or of death (RR 1.20, 95% CI 0.40 to 3.58). The second study was a substudy on the use of diazepam in acute stroke. It was a randomised double-blind study, comparing a three-day diazepam treatment versus placebo for primary seizure prevention up to three months after stroke in 784 adults with acute stroke. There was no evidence of a difference in the risk of post-stroke seizures for all stroke or subgroups of haemorrhagic or ischaemic stroke (RR for all stroke 0.47, 95% CI 0.18 to 1.22). In a subgroup analysis of anterior circulation cortical infarcts, primary prophylaxis with diazepam was associated with a reduced risk of post-stroke seizures (RR 0.21, 95% CI 0.05 to 0.95). Risks of mortality did not differ between the diazepam and the placebo group at two weeks (RR 0.84, 95% CI 0.56 to 1.26) and three months follow-up (RR 0.95, 95% CI 0.72 to 1.26). We assessed both studies to be at a low overall risk of bias. Using the GRADE approach, we assessed the overall certainty of the evidence as low to moderate. AUTHORS' CONCLUSIONS: There is insufficient evidence to support the routine use of AEDs on the primary and secondary prevention of seizures after stroke. Further well-conducted studies are warranted for this important clinical problem.


Assuntos
Isquemia Encefálica , Acidente Vascular Cerebral , Adulto , Anticonvulsivantes/efeitos adversos , Humanos , Ensaios Clínicos Controlados Aleatórios como Assunto , Prevenção Secundária , Convulsões/tratamento farmacológico , Convulsões/etiologia , Convulsões/prevenção & controle , Acidente Vascular Cerebral/tratamento farmacológico , Acidente Vascular Cerebral/prevenção & controle
17.
J Neurosci Res ; 100(4): 1030-1046, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35187710

RESUMO

Lateral entorhinal cortex (LEC) has been hypothesized to process nonspatial, item information that is combined with spatial information from medial entorhinal cortex to form episodic memories within the hippocampus. Recent studies, however, have demonstrated that LEC has a role in integrating features of episodic memory prior to the hippocampus. While the precise role of LEC is still unclear, anatomical studies show that LEC is ideally placed to be a hub integrating multisensory information. The current study tests whether the role of LEC in integrating information extends to long-term multimodal item-context associations. In Experiment 1, male rats were trained on a context-dependent odor discrimination task, where two different contexts served as the cue to the correct odor. Rats were pretrained on the task and then received either bilateral excitotoxic LEC or sham lesions. Following surgery, rats were tested on the previously learned odor-context associations. Control rats showed good memory for the previously learned association but rats with LEC lesions showed significantly impaired performance relative to both their own presurgery performance and to control rats. Experiment 2 went on to test whether impairments in Experiment 1 were the result of LEC lesions impairing either odor or context memory retention alone. Male rats were trained on simple odor and context discrimination tasks that did not require integration of features to solve. Following surgery, both LEC and control rats showed good memory for previously learned odors and contexts. These data show that LEC is critical for long-term odor-context associative memory.


Assuntos
Córtex Entorrinal , Odorantes , Animais , Hipocampo , Masculino , Memória , Ratos
18.
Heliyon ; 8(12): e12356, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36590473

RESUMO

Bovine tuberculosis (bTB) is a global disease of livestock that has damaging economic, animal health and public health consequences. Conventional bTB disease control strategies, based around the testing and slaughter of cattle infected with bTB, are typically used to help limit or reduce the transmission of this disease but in many low- and middle-income countries such strategies may often be economically unviable, culturally unacceptable or logistically impracticable. The use of vaccination to protect cattle against bTB could provide a potentially more affordable, ethically acceptable and practical additional disease control measure. The protective efficacy of the commercially produced and readily available human vaccine against tuberculosis (Mycobacterium bovis Bacille Calmette-Guérin; BCG) in cattle has been demonstrated in many experimental laboratory and field studies. However, Good Laboratory Practice (GLP) studies assessing the safety of BCG vaccination in cattle have not previously been reported. We describe here the results of two GLP safety studies in which calves and lactating cows were vaccinated with BCG (Danish 1331 strain). From an animal health and welfare perspective, the results of these studies indicate that BCG vaccine is well tolerated in these categories of cattle with only transient and minor local or systemic reactions. Furthermore, there was no evidence that BCG was shed in raw milk, saliva or faeces collected from vaccinates and vaccination did not have a detrimental effect on milk yields in lactating cattle. These data, underpinned by GLP principles, further support the existing data on the safety of BCG vaccine in cattle and complement the abundant available cattle efficacy data for this potential cattle bTB vaccine.

19.
Mol Ecol ; 31(23): 6141-6154, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-33657651

RESUMO

In many vertebrate societies dominant individuals breed at substantially higher rates than subordinates, but whether this hastens ageing remains poorly understood. While frequent reproduction may trade off against somatic maintenance, the extraordinary fecundity and longevity of some social insect queens highlight that breeders need not always suffer more rapid somatic deterioration than their nonbreeding subordinates. Here, we used extensive longitudinal assessments of telomere dynamics to investigate the impact of dominance status on within-individual age-related changes in somatic integrity in a wild social bird, the white-browed sparrow-weaver (Plocepasser mahali). Dominant birds, who monopolise reproduction, had neither shorter telomeres nor faster telomere attrition rates over the long-term (1-5 years) than their subordinates. However, over shorter (half-year) time intervals dominants with shorter telomeres showed lower rates of telomere attrition (and evidence suggestive of telomere lengthening), while the same was not true among subordinates. Dominants may therefore invest more heavily in telomere length regulation (and/or somatic maintenance more broadly); a strategy that could mitigate the long-term costs of reproductive effort, leaving their long-term telomere dynamics comparable to those of subordinates. Consistent with the expectation that reproduction entails short-term costs to somatic integrity, telomere attrition rates were most severe for all birds during the breeding seasons of wetter years (rainfall is the key driver of reproductive activity in this arid-zone species). Our findings suggest that, even in vertebrate societies in which dominants monopolise reproduction, dominants may experience long-term somatic integrity trajectories indistinguishable from those of their nonreproductive subordinates.


Assuntos
Predomínio Social , Pardais , Animais , Animais Selvagens , Reprodução/genética , Pardais/fisiologia , Telômero/genética
20.
Biol Lett ; 17(10): 20210409, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34665991

RESUMO

As telomere length (TL) often predicts survival and lifespan, there is considerable interest in the origins of inter-individual variation in TL. Cross-generational effects of parental age on offspring TL are thought to be a key source of variation, but the rarity of longitudinal studies that examine the telomeres of successive offspring born throughout the lives of parents leaves such effects poorly understood. Here, we exploit TL measures of successive offspring produced throughout the long breeding tenures of parents in wild white-browed sparrow weaver (Plocepasser mahali) societies, to isolate the effects of within-parent changes in age on offspring TLs. Our analyses reveal the first evidence to date of a positive within-parent effect of advancing age on offspring TL: as individual parents age, they produce offspring with longer telomeres (a modest effect that persists into offspring adulthood). We consider the potential for pre- and post-natal mechanisms to explain our findings. As telomere attrition predicts offspring survival to adulthood in this species, this positive parental age effect could impact parent and offspring fitness if it arose via differential telomere attrition during offspring development. Our findings support the view that cross-generational effects of parental age can be a source of inter-individual variation in TL.


Assuntos
Pardais , Telômero , Animais , Animais Selvagens , Longevidade , Telômero/genética , Encurtamento do Telômero
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...