Cognition in vestibular disorders: state of the field, challenges, and priorities for the future

Vestibular disorders are prevalent and debilitating conditions of the inner ear and brain which affect balance, coordination, and the integration of multisensory inputs. A growing body of research has linked vestibular disorders to cognitive problems, most notably attention, visuospatial perception, spatial memory, and executive function. However, the mechanistic bases of these cognitive sequelae remain poorly defined, and there is a gap between our theoretical understanding of vestibular cognitive dysfunction, and how best to identify and manage this within clinical practice. This article takes stock of these shortcomings and provides recommendations and priorities for healthcare professionals who assess and treat vestibular disorders, and for researchers developing cognitive models and rehabilitation interventions. We highlight the importance of multidisciplinary collaboration for developing and evaluating clinically relevant theoretical models of vestibular cognition, to advance research and treatment

Modern lineages of Mycobacterium tuberculosis exhibit lineage-specific patterns of growth and cytokine induction in human monocyte-derived macrophages

BACKGROUND: Strains of Mycobacterium tuberculosis vary in virulence. Strains that have caused outbreaks in the United States and United Kingdom have been shown to subvert the innate immune response as a potential immune evasion mechanism. There is, however, little information available as to whether these patterns of immune subversion are features of individual strains or characteristic of broad clonal lineages of M. tuberculosis . METHODS: Strains from two major modern lineages (lineage 2 [East-Asian] and lineage 4 [Euro-American]) circulating in the Western Cape in South Africa as well as a comparator modern lineage (lineage 3 [CAS/Delhi]) were identified. We assessed two virulence associated characteristics: mycobacterial growth (in liquid broth and monocyte derived macrophages) and early pro-inflammatory cytokine induction. RESULTS: In liquid culture, Lineage 4 strains grew more rapidly and reached higher plateau levels than other strains (lineage 4 vs. lineage 2 p = 0.0024; lineage 4 vs. lineage 3 p = 0.0005). Lineage 3 strains were characterized by low and early plateau levels, while lineage 2 strains showed an intermediate growth phenotype. In monocyte-derived macrophages, lineage 2 strains grew faster than lineage 3 strains (p<0.01) with lineage 4 strains having an intermediate phenotype. Lineage 2 strains induced the lowest levels of pro-inflammatory TNF and IL-12p40 as compared to other lineages (lineage 2: median TNF 362 pg/ml, IL-12p40 91 pg/ml; lineage 3: median TNF 1818 pg/ml, IL-12p40 123 pg/ml; lineage 4: median TNF 1207 pg/ml, IL-12p40 205 pg/ml;). In contrast, lineage 4 strains induced high levels of IL-12p40 and intermediate level of TNF. Lineage 3 strains induced high levels of TNF and intermediate levels of IL-12p40. CONCLUSIONS: Strains of M. tuberculosis from the three major modern strain lineages possess distinct patterns of growth and cytokine induction. Rapid growth and immune subversion may be key characteristics to the success of these strains in different human populations

Mechanisms and roles of mitochondrial localisation and dynamics in neuronal function

Neurons are highly polarised, complex and incredibly energy intensive cells, and their demand for ATP during neuronal transmission is primarily met by oxidative phosphorylation by mitochondria. Thus, maintaining the health and efficient function of mitochondria is vital for neuronal integrity, viability and synaptic activity. Mitochondria do not exist in isolation, but constantly undergo cycles of fusion and fission, and are actively transported around the neuron to sites of high energy demand. Intriguingly, axonal and dendritic mitochondria exhibit different morphologies. In axons mitochondria are small and sparse whereas in dendrites they are larger and more densely packed. The transport mechanisms and mitochondrial dynamics that underlie these differences, and their functional implications, have been the focus of concerted investigation. Moreover, it is now clear that deficiencies in mitochondrial dynamics can be a primary factor in many neurodegenerative diseases. Here, we review the role that mitochondrial dynamics play in neuronal function, how these processes support synaptic transmission and how mitochondrial dysfunction is implicated in neurodegenerative disease

Brassica and Sinapis Seeds in Medieval Archaeological Sites:An Example of Multiproxy Analysis for Their Identification and Ethnobotanical Interpretation

The genus Brassica includes some of the most important vegetable and oil crops worldwide. Many Brassica seeds (which can show diagnostic characters useful for species identification) were recovered from two archaeological sites in northern Italy, dated from between the Middle Ages and the Renaissance. We tested the combined use of archaeobotanical keys, ancient DNA barcoding, and references to ancient herbarium specimens to address the issue of diagnostic uncertainty. An unequivocal conventional diagnosis was possible for much of the material recovered, with the samples dominated by five Brassica species and Sinapis. The analysis using ancient DNA was restricted to the seeds with a Brassica-type structure and deployed a variant of multiplexed tandem PCR. The quality of diagnosis strongly depended on the molecular locus used. Nevertheless, many seeds were diagnosed down to species level, in concordance with their morphological identification, using one primer set from the core barcode site (matK). The number of specimens found in the Renaissance herbaria was not high; Brassica nigra, which is of great ethnobotanical importance, was the most common taxon. Thus, the combined use of independent means of species identification is particularly important when studying the early use of closely related crops, such as Brassicaceae

Cognition in vestibular disorders: state of the field, challenges, and priorities for the future

Vestibular disorders are prevalent and debilitating conditions of the inner ear and brain which affect balance, coordination, and the integration of multisensory inputs. A growing body of research has linked vestibular disorders to cognitive problems, most notably attention, visuospatial perception, spatial memory, and executive function. However, the mechanistic bases of these cognitive sequelae remain poorly defined, and there is a gap between our theoretical understanding of vestibular cognitive dysfunction, and how best to identify and manage this within clinical practice. This article takes stock of these shortcomings and provides recommendations and priorities for healthcare professionals who assess and treat vestibular disorders, and for researchers developing cognitive models and rehabilitation interventions. We highlight the importance of multidisciplinary collaboration for developing and evaluating clinically relevant theoretical models of vestibular cognition, to advance research and treatment

Chewing gum and impasse-induced self-reported stress

An insoluble anagram task (Zellner et al., 2006) was used to investigate the proposition that chewing gum reduces self-rated stress (Scholey et al., 2009). Using a between-participants design, forty participants performed an insoluble anagram task followed by a soluble anagram task. These tasks were performed with or without chewing gum. Self-rated measures were taken at baseline, post-stressor, and post-recovery task. The insoluble anagram task was found to amplify stress in terms of increases in self-rated stress and reductions in both self-rated calmness and contentedness. However, chewing gum was found not to mediate the level of stress experienced. Furthermore, chewing gum did not result in superior performance on the soluble anagram task. The present study fails to generalise the findings of Scholey et al. to an impasse induced stress that has social components. The explanation for the discrepancy with Scholey et al. is unclear; however, it is suggested that the impossibility of the insoluble anagram task may negate any secondary stress reducing benefits arising from chewing gum-induced task improvement

Susceptibility to increased high energy dense sweet and savoury food intake in response to the COVID-19 lockdown: The role of craving control and acceptance coping strategies

Emerging evidence indicates that for some people, the COVID-19 lockdowns are a time of high risk for increased food intake. A clearer understanding of which individuals are most at risk of over-eating during the lockdown period is needed to inform interventions that promote healthy diets and prevent weight gain during lockdowns. An online survey collected during the COVID-19 lockdown (total n = 875; analysed n = 588; 33.4 ± 12.6 years; 82% UK-based; mostly white, educated, and not home schooling) investigated reported changes to the amount consumed and changes to intake of high energy dense (HED) sweet and savoury foods. The study also assessed which eating behaviour traits predicted a reported increase of HED sweet and savoury foods and tested whether coping responses moderated this relationship. Results showed that 48% of participants reported increased food intake in response to the COVID-19 lockdown. There was large individual variability in reported changes and lower craving control was the strongest predictor of increased HED sweet and savoury food intake. Low cognitive restraint also predicted greater increases in HED sweet snacks and HED savoury meal foods. Food responsiveness, enjoyment of food, emotional undereating, emotional overeating and satiety responsiveness were not significant predictors of changes to HED sweet and savoury food intake. High scores on acceptance coping responses attenuated the conditional effects of craving control on HED sweet snack intake. Consistent with previous findings, the current research suggests that low craving control is a risk factor for increased snack food intake during lockdown and may therefore represent a target for intervention

A systematic review of vestibular stimulation in post-stroke visual neglect

Unilateral visual neglect is a condition that negatively impacts the lives of many stroke survivors. Studies have investigated different forms of vestibular stimulation as a potential therapy, but evidence is yet to be systematically reviewed. We therefore reviewed the effects of vestibular stimulation on outcomes of neglect and activities of daily living (ADL) for people with visual neglect. We searched relevant databases up until September 2022. Eligible articles included any form of vestibular stimulation, study design, or control condition. Included participants were 18 years or older, presenting with neglect following a haemorrhagic or ischaemic stroke. Relevant outcomes were clinically validated measures of neglect and ADL. Cochrane risk of bias tools were used to assess study quality. Meta-analyses and narrative methods were used to synthesize the data. Our search returned 17 relevant studies comprising 180 participants. Meta-analyses showed no difference between galvanic vestibular stimulation and sham conditions on outcomes, whereas caloric vestibular stimulation led to improvement compared to pre-stimulation scores. Narrative syntheses showed mixed results. Clinical and methodological heterogeneity was found both within and between studies. Overall, results were inconsistent regarding the effects of vestibular stimulation as a treatment for neglect. Further trials are warranted but require more careful methodological planning

Hookworm infection, anaemia and genetic variability of the New Zealand sea lion

Hookworms are intestinal blood-feeding nematodes that parasitize and cause high levels of mortality in a wide range of mammals, including otariid pinnipeds. Recently, an empirical study showed that inbreeding (assessed by individual measures of multi-locus heterozygosity) is associated with hookworm-related mortality of California sea lions. If inbreeding increases susceptibility to hookworms, effects would expectedly be stronger in small, fragmented populations. We tested this assumption in the New Zealand sea lion, a threatened otariid that has low levels of genetic variability and high hookworm infection rates. Using a panel of 22 microsatellites, we found that average allelic diversity (5.9) and mean heterozygosity (0.72) were higher than expected for a small population with restricted breeding, and we found no evidence of an association between genetic variability and hookworm resistance. However, similar to what was observed for the California sea lion, homozygosity at a single locus explained the occurrence of anaemia and thrombocytopenia in hookworm-infected pups (generalized linear model, F = 11.81, p < 0.001) and the effect was apparently driven by a particular allele (odds ratio = 34.95%; CI: 7.12–162.41; p < 0.00001). Our study offers further evidence that these haematophagus parasites exert selective pressure on otariid blood-clotting processes

Effects of a nonlinear perturbation on dynamical tunneling in cold atoms

We perform a numerical analysis of the effects of a nonlinear perturbation on the quantum dynamics of two models describing non-interacting cold atoms in a standing wave of light with a periodical modulated amplitude $A(t)$. One model is the driven pendulum, considered in ref.\cite{raiz1}, and the other is a variant of the well-known Kicked Rotator Model. In absence of the nonlinear perturbation, the system is invariant under some discrete symmetries and quantum dynamical tunnelling between symmetric classical islands is found. The presence of nonlinearity destroys tunnelling, breaking the symmetries of the system. Finally, further consequences of nonlinearity in the kicked rotator case are considered.Comment: 10 pages, 15 figure