European Journal of Neuroscience最新文献

Cerebral lateralization of written language, much like oral language, is predominantly left lateralized. However, handwriting has been the primary focus in lateralization studies. The cerebral lateralization of typing—a widely used method of writing—remains unexamined. This preregistered study aimed to explore the cerebral lateralization of typing versus handwriting and to investigate possible handedness-related differences. We hypothesized that (i) cerebral lateralization would not differ between the two writing methods after movement correction and (ii) both handwriting and typing would show weaker lateralization in left-handers compared to right-handers. To investigate this, we used functional transcranial Doppler (fTCD) ultrasound, a reliable method for assessing cerebral lateralization during language tasks that remains unaffected by movement artifacts, such as those generated by handwriting and typing. A total of 24 left-handers and 30 right-handers participated, performing written word generation through both handwriting and typing on a computer keyboard while undergoing fTCD assessment. We applied a Bayesian framework for our analysis, as it enables us to demonstrate the absence of a difference (i.e., no difference between two variables), which is not possible with the use of p values (estimated under the frequentist framework). Our results provided evidence supporting the absence of a difference in cerebral lateralization between handwriting and typing after movement correction. However, we found no conclusive evidence to either support or refute a difference in lateralization between left-handers and right-handers, suggesting that more research is needed to clarify the role of handedness in cerebral lateralization for different writing methods.

Aberrant microtubule dynamics coupled with a reduction in Tau-microtubule interaction are at the core of neuronal injuries resulting in microtubule disruption and aggregates of abnormally phosphorylated Tau. These pathological Tau aggregates define tauopathies such as Alzheimer's disease (AD), as well as the pathological sequelae following traumatic brain injury (TBI), stroke and spinal cord injury (SCI). We hypothesized that differential applications of extremely low-frequency and low-intensity electromagnetic field (ELF-EMF) will change microtubule function. To examine our hypothesis, we pre-applied ELF-EMF to a neuroblastoma neuronal cell line later exposed to 4 h of zinc intoxication, modelling Tau-microtubule dissociation. ELF-EMF (40 Hz and 1 G; multiple exposure schedules) enhanced microtubule dynamics and increased Tau-microtubule interaction in the face of zinc toxicity. Complementing these preconditioning neuroprotective effects, concomitant 1 h treatment protocols comparing 3.9 or 40 Hz and 1 G exposure, indicated effects on Tau phosphorylation accentuated with 40 Hz and reduction in beta tubulin isotypes, depending on electromagnetic frequencies, most pronounced at 3.9 Hz. Our results discovered ELF-EMF modulation on the microtubule cytoskeleton essential for brain health.

Recent studies have reported social cognitive deficits, particularly in emotional processing, in Parkinson's disease (PD). However, a comprehensive characterization of these deficits and their underlying neural correlates remains elusive. Therefore, this study aims to investigate the association between deficits in the recognition of complex mental states and structural/functional brain changes in non-demented PD individuals. To reach this aim, 24 PD participants underwent clinical assessment, neuropsychological testing and the FAcial Complex Expressions (FACE) test, a novel test of complex mental state recognition from faces. Patients were classified as clinically impaired (n = 8) or unimpaired (n = 16) based on performance on this test. Magnetic resonance imaging data were acquired to investigate the association between FACE test performance and both resting-state functional connectivity and grey matter volume, within the emotion understanding network and at the whole-brain level. Statistical analyses also included the comparison of imaging metrics between the impaired and unimpaired groups. Results showed that complex mental state recognition in PD was significantly associated with both defective and compensatory mechanisms at the functional and anatomical level within the emotion understanding network, particularly involving the amygdala, dorsomedial prefrontal cortex, primary/secondary somatosensory cortices, and right anterior temporal cortex. Whole-brain results extended the network to temporal and medial frontal areas. In conclusion, reduced recognition of complex mental states in non-demented PD patients is associated with alterations in the emotion understanding network A comprehensive characterization of early emotional deficits in these patients may have significant implications in the characterization of the cognitive phenotype, with potential benefit for tailored non-pharmacological intervention.

School-aged and adolescent survivors of neonatal extracorporeal membrane oxygenation (ECMO) treatment still suffer from neurodevelopmental delays such as verbal, visuo-spatial and working memory problems, motor dysfunction and sensorineural hearing loss, respectively, later in life, which is well-documented by neuropsychological testing within follow-up programs. In this study, we demonstrate that diffusion-weighted imaging (DWI) in 2-year-old survivors of neonatal ECMO treatment reveals white matter (WM) alterations in brain regions related to neurodevelopmental outcome seen later in life. From the DWI data of 56 children, fractional anisotropy (FA), first fibre partial volume fraction estimate (F1), radial diffusivity (RD) and mean diffusivity (MD) are calculated and compared using tract-based spatial statistics adapted to a paediatric brain atlas. Significant differences in FA, F1, RD and MD between the no-ECMO and ECMO groups are seen in major WM tracts. Additionally, we examine individual diffusion measures by looking at 50 regions supplied with the paediatric brain atlas. We find the following regions to have significantly different means in the no-ECMO compared with the ECMO group matching reports of neuropsychological delays found in behavioural tests: left anterior corona radiata, left anterior limb of internal capsule, left anterior commissure, left and right corpus callosum (genu, body and splenium), left and right crus of fornix and left tapetum. Analysing diffusion measures at an early stage of life serves as a good tool to detect structural WM changes in survivors of neonatal ECMO treatment. Compared with neuropsychological testing, DWI does not depend on the child's active participation.

The link between subthalamic nucleus deep brain stimulation (STN-DBS) and apathy in patients with Parkinson's disease (PD) remains a controversial topic. The literature is mixed and the most supported explanation is the reduction of dopaminergic treatment. Yet a body of clinical and experimental evidences suggest that STN-DBS itself can also promote apathy in certain patients. However, the parameters accounting for apathy heterogeneity in stimulated patients along with the mechanisms underlying apathy induced by STN-DBS remain to be investigated. Whether bilateral and unilateral STN-DBS have the same influence on apathy is for instance unknown. We previously and separately showed in patients and rodents that bilateral STN-DBS can promote apathy per se. Here, we compare the effect of bilateral versus unilateral STN-DBS both in patients and in rodents. We conducted a clinical follow-up of patients with Parkinson's disease undergoing unilateral or bilateral STN-DBS and assessing apathy 3 months before and after STN-DBS. In parallel, we applied chronic and uninterrupted unilateral or bilateral DBS in rodents and extract longitudinal motivational changes with a battery of behavioural tests. While bilateral STN-DBS promotes apathy in patients and induces a loss of motivation in rodents, we found that unilateral STN-DBS did not exert such an effect both in patients and in rats. These data show that bilateral but not unilateral STN-DBS promotes apathy. This not only substantiate the induction of neuropsychiatric effects by STN-DBS but also suggest that this might be circumvented if STN-DBS is applied unilaterally instead of bilaterally.

Interoception, the internal perception of bodily states such as heartbeat and hunger, plays a crucial role in shaping cognitive and emotional states. Since postural control affects cognitive and emotional processing, exploring postural effects on interoception could help uncover the neural mechanisms underlying its effects on cognition and emotion. In this study, we aimed to investigate how different postures affect interoception by using heartbeat-evoked potentials (HEPs), which reflect the cortical processing of cardiac signals. Two experiments were conducted; Experiment 1 involved 47 healthy male participants comparing sitting and standing postures, and Experiment 2 involved 24 healthy male participants comparing stable and unstable standing conditions. HEPs were analyzed using cluster-based permutation analysis to identify statistically significant spatiotemporal clusters. In Experiment 1, significant clusters were identified over central electrodes (Cz, C1, C2, FCz, and FC1) within the post-R-wave interval of 304–572 ms, revealing significantly lower HEP amplitudes during standing compared to sitting [W = 80, p < 0.001, r = 0.62]. In Experiment 2, HEP amplitudes were significantly lower during unstable standing compared to stable standing [t(20) = 2.9, p = 0.0099, d = 0.62]. Furthermore, we found no significant correlations between HEP changes and physiological changes such as cardiac activity and periodic and aperiodic brain activity. These findings suggest postural differences modulate interoceptive processing, with standing postures attenuating HEP amplitudes, probably because of a redistribution of attentional resources from interoceptive to somatosensory (proprioceptive) and vestibular processing, necessary for maintaining standing posture. This study provides insights into the neural mechanisms underlying posture–interoception interaction.

Autism spectrum condition is a neurodevelopmental condition with difficulties in social interaction, communication and repetitive behaviours. Autistic individuals often exhibit difficulties in non-social cognitive processing, such as grouping items into meaningful categories based on their holistic visual appearance. Underlying mechanisms might be a deficit in abstracting a category's central tendency (i.e., the prototype) or more general atypicalities in visual category learning processes. Milder autistic traits often also extend to a broader autism phenotype in neurotypical individuals. Our study compared adult neurotypical individuals with high or low autistic traits on behavioural performances and neural correlates measured by event-related functional magnetic resonance imaging (fMRI) during a single-category perceptual categorization task, based on the well-known dot-pattern paradigm. Bayesian computational modelling was used to investigate links between autistic traits and representing category knowledge by the prototype or memorizing single exemplars. We found that a high degree of autistic traits was linked to worse accuracy for endorsing category members. Autistic trait groups also differed in neural correlates during the training phase related to visual processing in occipital regions, decision-making in midfrontal regions and the posterior cingulate, and feedback processing in the posterior cingulate and the ventral striatum. Model-based analyses did not support deficits in prototype abstraction but yielded a link between autistic traits and stricter decision policies. In sum, we found no relationship between high autistic traits and difficulties with the prototype strategy but more general atypicalities in visual category learning processes, namely, visual processing, decision-making and feedback processing.