Brain and neuroscience advances最新文献

In their recently published study, Gil, Valente and Shemesh combined behaviour, functional magnetic resonance imaging, electroencephalography and causal interventions to establish and validate a cortical processing substrate underlying the transition from static to dynamic visual states in the rat. Their research highlights the superior colliculus as the primary mediator of visual temporal discrimination by showing a direct correlation between behavioural and cortically derived flicker fusion frequency thresholds. This work provides the first empirical evidence addressing the previously established disparity between behavioural and cortically derived flicker fusion frequency thresholds. It demonstrates how important convergent multimodal approaches are to mapping and validating previously disputed cortical pathways. Here, we discuss and evaluate their work, suggesting possible future applications in the field of behavioural neuroscience.

Ischaemic stroke presents a significant problem worldwide with no neuroprotective drugs available. Many of the failures in the search for neuroprotectants are attributed to failure to translate from pre-clinical models to humans, which has been combatted with rigorous pre-clinical stroke research guidelines. Here, we present post hoc analysis of a pre-clinical stroke trial, conducted using intraluminal filament transient middle cerebral artery occlusion in the stroke-prone spontaneously hypertensive rat, whereby unscheduled changes were implemented in the animal housing facility. These changes severely impacted body weight post-stroke resulting in a change from the typical body weight of 90.6% of pre-surgery weight post-stroke, to on average 80.5% of pre-surgery weight post-stroke. The changes also appeared to impact post-stroke blood pressure, with an increase from 215.4 to 240.3 mmHg between housing groups, and functional outcome post-stroke, with a 38% increased latency to contact in the sticky label test. These data highlight the importance of tightly controlled housing conditions when using physiological or behavioural measurements as a primary outcome.

The modulation of synaptic efficacy by group I metabotropic glutamate receptors is dysregulated in several neurodevelopmental and neurodegenerative disorders impacting cognitive function. The progression and severity of these and other disorders are affected by biological sex, and differences in metabotropic glutamate receptor signalling have been implicated in this effect. In this study, we have examined whether there are any sex-dependent differences in a form of long-term depression of synaptic responses that is triggered by application of the group I metabotropic glutamate receptor agonist 3,5-dihydroxyphenylglycine (DHPG). We studied DHPG-induced long-term depression at the Schaffer collateral-commissural pathway in area CA1 of hippocampal slices prepared from three separate age groups of Sprague Dawley rats. In both juvenile (2-week-old) and young adult (3-month-old) rats, there were no differences between sexes in the magnitude of long-term depression. However, in older adult (>1-year-old) rats, DHPG-induced long-term depression was greater in males. In contrast, there were no differences between sexes with respect to basal synaptic transmission or paired-pulse facilitation in any age group. The specific enhancement of metabotropic glutamate receptor-dependent long-term depression in older adult males, but not females, reinforces the importance of considering sex as a factor in the study and treatment of brain disorders.

A recent study by Blank, Alink and Büchel, uses multivariate neuroimaging to investigate how the human brain processes the strength of face-related expectations and explores whether these expectations are represented in the same regions that process facial stimuli. In line with predictive coding theories, their study presents compelling evidence that the brain adjusts its processing based on the certainty of expectations. This occurs exclusively within high-level face-sensitive regions, rather than across the entire processing hierarchy. Here we critically discuss these findings and outline potential directions for future research to better understand how the human brain expects, processes, and perceives images.

This article presents edited highlights from a special session at the BNA International Festival of Neuroscience held in Brighton in April 2023. The session involved Desert Island Disc-style interviews between early career researchers and established investigators, discussing papers that influenced their neuroscience careers.

Depression is a debilitating illness, and stigma associated with it often prevents people from seeking support. Easy-to-administer and culturally- inclusive tools can allow for early screening for depressive symptoms in primary care clinics, especially in resource-limited settings. In this pre-registered pilot study (Stage 1 Report available at DOI: 10.3389/fpsyt.2022.840912), we produced an open-access isiXhosa-language version of the nine-item Patient Health Questionnaire (PHQ-9), a well-validated measure of depression incidence and severity, using a transcultural translation framework. We validated this isiXhosa PHQ-9 in a sample of N = 47 adolescents living with and without HIV in Cape Town, South Africa who speak isiXhosa at home. Reliability, convergent validity, and criterion validity were assessed, with T scores on the Achenbach System of Empirically Based Assessment Youth Self Report (YSR) form completed previously as reference standard. Our isiXhosa PHQ-9 exhibited satisfactory reliability, with Cronbach's $\alpha =0.866$, inter-item correlations ranging from 0.229 to 0.730, and mean item-total correlation of 0.69. PHQ-9 score and Withdrawn/Depressed component T scores on the Youth Self Report were moderately associated (Spearman's $\rho =0.40,p=0.011)$, indicating acceptable convergent validity. The isiXhosa PHQ-9 showed satisfactory criterion validity (area under the receiver operating characteristic curve, AUC = 0.706), but these analyses were under-powered. Principal component analysis revealed a one-factor solution, with 45.8% of variance explained by the first principal component and all factor loadings above conventional thresholds. Our isiXhosa translation of the PHQ-9 thus exhibited satisfactory psychometric properties in this pilot validation study and performed comparably to other PHQ-9 versions validated in different languages in African and global contexts. This questionnaire may serve as an invaluable culturally-inclusive screening tool for measuring depressive symptoms among isiXhosa speakers. Caution must be exercised as screening tools including the PHQ-9 may over- or under-estimate prevalence of depression. Further validation in larger, independent cohorts may enable wider use of our isiXhosa PHQ-9 as a screening tool in clinics, research studies, and mental health non-profits who serve amaXhosa.

As a leading cause of mortality and morbidity, stroke and its management have been studied extensively. Despite numerous pre-clinical studies identifying therapeutic targets, development of effective, specific pharmacotherapeutics remain limited. One significant limitation is a break in the translational pipeline - promising pre-clinical results have not always proven replicable in the clinic. Recent developments in virtual reality technology might help generate a better understanding of injury and recovery across the whole research pipeline in search of optimal stroke management. Here, we review the technologies that can be applied both clinically and pre-clinically to stroke research. We discuss how virtual reality technology is used to quantify clinical outcomes in other neurological conditions that have potential to be applied in stroke research. We also review current uses in stroke rehabilitation and suggest how immersive programmes would better facilitate the quantification of stroke injury severity and patient recovery comparable to pre-clinical study design. By generating continuous, standardised and quantifiable data from injury onset to rehabilitation, we propose that by paralleling pre-clinical outcomes, we can apply a better reverse-translational strategy and apply this understanding to animal studies. We hypothesise this combination of translational research strategies may improve the reliability of pre-clinical research outcomes and culminate in real-life translation of stroke management regimens and medications.

Teriflunomide is an oral disease-modifying therapy for relapsing-remitting multiple sclerosis patients. A decline in physical and cognitive functions, which negatively impacts their quality of life (QoL), is observed in relapsing-remitting multiple sclerosis patients. The aim of this study was to characterise adult Portuguese relapsing-remitting multiple sclerosis patients treated with teriflunomide in routine clinical practice concerning their quality of life, comorbidities, treatment effectiveness, satisfaction, compliance and safety. TeriLIVE-QoL was a multicentre, non-interventional, prospective cohort study that collected demographic and clinical characteristics, patient-reported outcomes and adverse events from patients treated with teriflunomide of 14 mg over 2 years. Notably, around 18 months of this period occurred during the COVID-19 pandemic. Of the 99 participants, 25% were treatment-naïve. Annualised relapse rate and the score for the Hospital Anxiety and Depression Scale decreased after 1 (p = 0.01) and 2 years of treatment (p < 0.001), respectively. Convenience (p = 0.001), effectiveness (p = 0.002) and global satisfaction scores (p < 0.001) presented high values (up to 95.6) and continued to improve along the study. Treatment persistence was 77%, and compliance reached 82% 2 years after initiation. Three patients experienced serious adverse events. TeriLIVE-QoL provides real-world evidence of clinical effectiveness, high treatment satisfaction, consistent safety and improved psychiatric outcomes, associated with elevated treatment persistence and compliance in patients treated with teriflunomide.iance reached 82% 2 years after initiation. Three patients experienced serious adverse events.