PaperPlayer biorxiv neuroscience

Link to bioRxiv paper:

http://biorxiv.org/cgi/content/short/2020.11.22.393199v1?rss=1

Authors: Pistono, A., Senoussi, M., Guerrier, L., Rafiq, M., Gimeno, M., Peran, P., Jucla, M., Pariente, J.

Abstract:

Language production deficits occur early in the course of Alzheimer's disease (AD); however, only few studies have focused on language functional networks in prodromal AD. The current study aims to uncover the extent of language alteration at a prodromal stage, on a behavioral, structural and functional level, using univariate and multivariate analyses. Twenty-four AD participants and 24 matched healthy controls underwent a comprehensive language evaluation, a structural T1-3D MRI and resting-state fMRI. We performed seed-based analyses, using the left inferior frontal gyrus and left posterior temporal gyrus as seeds. Then, we analyzed connectivity between executive control networks and language network in each group. Finally, we used multivariate pattern analyses to test whether the two groups could be distinguished based on the pattern of atrophy within the language network; atrophy within the executive control networks, as well as the pattern of functional connectivity within the language network; and functional connectivity within executive control networks. AD participants had language impairment during standardized language tasks and connected-speech production. Univariate analyses were not able to discriminate participants at this stage, while multivariate pattern analyses could significantly predict the group membership of prodromal patients and healthy controls, both when classifying atrophy patterns or connectivity patterns of the language network. Language functional networks could discriminate AD participants better than executive control networks. Most notably, they revealed an increased connectivity at a prodromal stage. Multivariate analyses represent a useful tool for investigating the functional and structural (re-)organization of the neural bases of language.

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Link to bioRxiv paper:

http://biorxiv.org/cgi/content/short/2020.11.21.390229v1?rss=1

Authors: Hecht, E. E., Kukekova, A., Gutman, D. A., Acland, G. M., Preuss, T. M., Trut, L.

Abstract:

The Russian fox-farm experiment is an unusually long-running and well-controlled study designed to replicate wolf-to-dog domestication. As such, it offers an unprecedented window onto the neural mechanisms governing the evolution of behavior. Here we report adaptations to gray matter morphology resulting from selection for tameness vs. aggressive response toward humans. Contrasting with prior work in other domesticated species, tame foxes did not show reduced brain volume. Rather, gray matter volume in both the tame and aggressive strains was increased relative to foxes bred without selection on behavior. Furthermore, tame- and aggressive-enlarged regions overlapped substantially, including portions of motor, somatosensory, and prefrontal cortex, amygdala, hippocampus, and cerebellum. We also observed differential morphological covariation across distributed gray matter networks. In one prefrontal-hypothalamic network, this covariation differentiated the tame and aggressive foxes together from the conventional strain. These findings indicate that selection for opposite behaviors can influence brain morphology in a similar way.

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Link to bioRxiv paper:

http://biorxiv.org/cgi/content/short/2020.11.20.392258v1?rss=1

Authors: Huang, P., Correia, M. M., Rua, C., Rodgers, C. T., Henson, R. N., Carlin, J. D.

Abstract:

The arrival of submillimetre ultra high-field fMRI makes it possible to compare activation profiles across cortical layers. However, the Blood Oxygenation Level Dependent (BOLD) signal measured by Gradient-Echo fMRI is biased towards superficial layers of the cortex, which is a serious confound for laminar analysis. Several univariate and multivariate analysis methods have been proposed to correct this bias. We compare these methods using computational simulations and example human 7T fMRI data from Regions-of-Interest (ROIs) during a visual attention paradigm. The simulations show that two methods - the ratio of ROI means across conditions and a novel application of Deming regression - offer the most robust correction for superficial bias. Deming regression has the additional advantage that it does not require that the conditions differ in their mean activation over voxels within an ROI. When applied to the example dataset, these methods suggest that attentional modulation of activation is similar across cortical layers within the ventral visual stream, despite a naive activation-based analysis producing stronger modulation in superficial layers. Our study demonstrates that accurate correction of superficial bias is crucial to avoid drawing erroneous conclusions from laminar analyses of Gradient-Echo fMRI data.

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Link to bioRxiv paper:

http://biorxiv.org/cgi/content/short/2020.11.20.392274v1?rss=1

Authors: Fengler, A., Frank, M., Govindarajan, L., Chen, T.

Abstract:

In cognitive neuroscience, computational modeling can formally adjudicate between theories and affords quantitative fits to behavioral/brain data. Pragmatically, however, the space of plausible generative models considered is dramatically limited by the set of models with known likelihood functions. For many models, the lack of a closed-form likelihood typically impedes Bayesian inference methods. As a result, standard models are evaluated for convenience, even when other models might be superior. Likelihood-free methods exist but are limited by their computational cost or their restriction to particular inference scenarios. Here, we propose neural networks that learn approximate likelihoods for arbitrary generative models, allowing fast posterior sampling with only a one-off cost for model simulations that is amortized for future inference. We show that these methods can accurately recover posterior parameter distributions for a variety of neurocognitive process models. We provide code allowing users to deploy these methods for arbitrary hierarchical model instantiations without further training.

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Link to bioRxiv paper:

http://biorxiv.org/cgi/content/short/2020.11.20.391698v1?rss=1

Authors: Voldsbekk, I., Barth, C., Maximov, I. I., Kaufmann, T., Beck, D., Richard, G., Moberget, T., Westlye, L. T., de Lange, A.-M. G.

Abstract:

Maternal brain adaptations occur in response to pregnancy, but little is known about how parity impacts white matter (WM) microstructure and WM ageing trajectories later in life. Utilising global and regional brain-age prediction based on multi-shell diffusion MRI data, we investigated the association between previous childbirths and WM brain age in 8,895 women in the UK Biobank cohort (age range = 54 - 81 years). The results showed that a higher number of previous childbirths was associated with lower WM brain age, in line with previous studies showing less evident grey matter (GM) brain ageing in parous relative to nulliparous women. Both global WM and GM brain age estimates showed unique contributions to the association with previous childbirths, suggesting partly independent processes. Corpus callosum contributed uniquely to the global WM association with previous childbirths, and showed a stronger relationship relative to several other tracts. While our findings demonstrate a link between reproductive history and brain WM characteristics later in life, longitudinal studies are required to understand how parity influences women's WM trajectories across the lifespan.

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Link to bioRxiv paper:

http://biorxiv.org/cgi/content/short/2020.11.21.392910v1?rss=1

Authors: Zeng, Y., Qin, S., Cui, Z., Wu, L., Xu, J., Tao, F., Yang, Z.

Abstract:

The dynamical organization of brain networks is essential to support human cognition and emotion for rapid adaption to ever-changing environment. As the core nodes of emotion-related brain circuitry, the basolateral amygdala (BLA) and centromedial amygdala (CMA) are recognized as two major amygdalar nuclei that regulate distinct affective functions and internal autonomic responses via their unique connections with cortical and subcortical structures in rodents. However, little is known how the dynamical organization of emotion-related brain circuitry reflects internal autonomic responses in humans. Using resting-state functional magnetic resonance imaging (fMRI) with concurrent recording of skin conductance, we show robust dynamic integration and segregation states of amygdala subregion-related intrinsic functional networks linked to spontaneous autonomic arousal. To be specific, time-varying connectivity analysis of resting-state fMRI data with K-means clustering approach revealed two distinct states of BLA- and CMA-based connectivity patterns, with a segregation state showing generally stronger BLA- than CMA-based connectivity with cortical regions, and an integration state showing substantial overlapping, in a spatio-temporal manner, between BLA- and CMA-based connectivity networks. Further analysis of skin conductance revealed significantly higher physiological arousal during the integration state than the segregation state, and state-specific BLA- and CMA-based connectivity with distinct subcortical and neocortical targets were predictive of spontaneous fluctuations of skin conductance. Our findings characterize dynamic functional organization of emotion-related amygdala nuclei circuits and networks and its links to spontaneous autonomic arousal in humans.

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Link to bioRxiv paper:

http://biorxiv.org/cgi/content/short/2020.11.22.392985v1?rss=1

Authors: Noro, Y., Shimizu, H., Mineta, K., Gojobori, T.

Abstract:

The last common ancestor of Bilateria and Cnidaria is believed to be one of the first animals to develop a nervous system over 500 million years ago. Many of the genes involved in the neural function of the advanced nervous system in Bilateria are well conserved in Cnidaria. Thus, Cnidarian representative species, Hydra, is considered to be a living fossil and a good model organism for the study of the putative primitive nervous system in its last common ancestor. The diffuse nervous system of Hydra consists of several peptidergic neuron subsets. However, the specific functions of these subsets remain unclear. Using calcium imaging, here we show that the neuron subsets that express neuropeptide, Hym-176 function as motor neurons to evoke longitudinal contraction. We found that all neurons in a subset defined by the Hym-176 gene (Hym-176A) or its paralogs (Hym-176B) expression are excited simultaneously, which is then followed by longitudinal contraction. This indicates not only that these neuron subsets are motor neurons but also that a single molecularly defined neuron subset forms a single coactive motor circuit. This is in contrast with the Bilaterian nervous system, where a single molecularly defined neuron subset harbors multiple coactive circuits, showing a mixture of neurons firing with different timings. Furthermore, we found that the two motor circuits, one expressing Hym-176B in the body column and the other expressing Hym-176A in the foot, are coordinately regulated to exert region-specific contraction. Our results demonstrate that one neuron subset is likely to form a monofunctional circuit as a minimum functional unit to build a more complex behavior in Hydra. We propose that this simple feature (one subset, one circuit, one function) found in Hydra is a fundamental trait of the primitive nervous system.

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Link to bioRxiv paper:

http://biorxiv.org/cgi/content/short/2020.11.22.393355v1?rss=1

Authors: Tran, T. T., Tobin, K. E., Block, S. H., Puliyadi, V., Gallagher, M., Bakker, A.

Abstract:

There has been considerable focus on investigating age-related memory changes in cognitively healthy older adults, in the absence of neurodegenerative disorders. Previous studies have reported age-related domain-specific changes in older adults, showing increased difficulty encoding and processing object information but minimal to no impairment in processing spatial information compared to younger adults. However, few of these studies have examined age-related changes in the encoding of concurrently presented object and spatial stimuli, specifically the integration of both spatial and non-spatial (object) information. To more closely resemble real-life memory encoding and the integration of both spatial and non-spatial information, the current study developed a new experimental paradigm with novel environments that allowed for the placement of different objects in different positions within the environment. The current findings show that older adults have decreased performance in recognizing changes of the object position within the spatial context but no significant differences in recognizing changes in the identity of the object within the spatial context compared to younger adults. These findings suggest there may be potential age-related differences in the mechanisms underlying the representations of complex environments and furthermore, the integration of spatial and non-spatial information may be differentially processed relative to independent and isolated representations of object and spatial information.

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Link to bioRxiv paper:

http://biorxiv.org/cgi/content/short/2020.11.21.392563v1?rss=1

Authors: Cataldo, A., Dupin, L., Dempsey-Jones, H., Gomi, H., Haggard, P.

Abstract:

Classical accounts of spatial perception are based either on the topological layout of sensory receptors, or on implicit spatial information provided by motor commands. In everyday self-touch, as when stroking the left arm with the right hand, these elements are inextricably linked, meaning that tactile and motor contributions to spatial perception cannot readily be disentangled. Here, we developed a robot-mediated form of self-touch in order to decouple the spatial extent of active or passive movements from their tactile consequences. Participants judged the spatial extent of either the movement of the right hand, or of the resulting tactile stimulation to their left forearm. Across five experiments, we found bidirectional interference between motor and tactile information. Crucially, both directions of interference were stronger during active than passive movements. Thus, voluntary motor commands produced stronger integration of multiple signals relevant to spatial perception.

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Link to bioRxiv paper:

http://biorxiv.org/cgi/content/short/2020.11.21.392449v1?rss=1

Authors: Baik, S.-H., Selvaraji, S., Fann, D. Y., Jo, D.-G., Herr, D. R., Lai, M. K. P., Chen, C. L.-H., Drummond, G. R., Lim, K.-L., Sobey, C. G., Arumugam, T.

Abstract:

Vascular dementia (VaD) is a progressive cognitive impairment of vascular etiology. VaD is characterized by cerebral hypoperfusion, increased blood-brain barrier permeability and white matter lesions. An increased burden of VaD is expected due to rapidly aging populations. The hippocampus is particularly susceptible to hypoperfusion, and the resulting memory impairment may play a crucial role in VaD. Here we have investigated the hippocampal gene expression profile of young and old mice subjected to chronic cerebral hypoperfusion by bilateral common carotid artery stenosis (BCAS). Our data in sham-operated young and aged mice show the normal age-associated decline in cerebral blood flow and differential gene expression. BCAS and ageing caused broadly similar effects, however, BCAS-induced changes in hippocampal gene expression differed between young and aged mice. Specifically, transcriptomic analysis indicated that in comparison to young sham mice, many pathways altered by BCAS in young mice resembled those present in sham aged mice. Immunoblot analyses confirmed these findings. Finally, relative to young sham mice the cell type-specific profile of genes in both young BCAS and old sham animals further revealed common cell-specific genes. Our data provide a genetic-based molecular framework for chronic hypoperfusion-induced hippocampal damage and reveal common cellular signaling pathways likely to be important in the pathophysiology of VaD.

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