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Prosodic categories in sp...
Forum: General Neuroscience talk
Last Post: BioRxiv
4 hours ago
» Replies: 0
» Views: 0
Histone Deacetylase 2 (HD...
Forum: General Neuroscience talk
Last Post: BioRxiv
4 hours ago
» Replies: 0
» Views: 0
Distributed networks for ...
Forum: General Neuroscience talk
Last Post: BioRxiv
4 hours ago
» Replies: 0
» Views: 0
Local Shape Descriptors f...
Forum: General Neuroscience talk
Last Post: BioRxiv
4 hours ago
» Replies: 0
» Views: 0
Cholinergic signalling in...
Forum: General Neuroscience talk
Last Post: BioRxiv
4 hours ago
» Replies: 0
» Views: 0
Intracranial electrical s...
Forum: General Neuroscience talk
Last Post: BioRxiv
4 hours ago
» Replies: 0
» Views: 0
Development of a Semantic...
Forum: General Neuroscience talk
Last Post: BioRxiv
4 hours ago
» Replies: 0
» Views: 2
Behavioral, Physiological...
Forum: Hot topics in neuroscience
Last Post: Cell
4 hours ago
» Replies: 0
» Views: 0
Subcircuits of Deep and S...
Forum: Hot topics in neuroscience
Last Post: Cell
4 hours ago
» Replies: 0
» Views: 0
A Visual Circuit Related ...
Forum: Hot topics in neuroscience
Last Post: Cell
4 hours ago
» Replies: 0
» Views: 0

 
  Prosodic categories in speech are acoustically multidimensional: evidence from dim
Posted by: BioRxiv - 4 hours ago - Forum: General Neuroscience talk - No Replies

Prosodic categories in speech are acoustically multidimensional: evidence from dim


Segmental speech units (e.g. phonemes) are described as multidimensional categories wherein perception involves contributions from multiple acoustic input dimensions, and the relative perceptual weights of these dimensions respond dynamically to context. Can prosodic aspects of speech spanning multiple phonemes, syllables or words be characterized similarly? Here we investigated the relative contribution of two acoustic dimensions to word emphasis. Participants categorized instances of a two-word phrase pronounced with typical covariation of fundamental frequency (F0) and duration, and in the context of an artificial accent in which F0 and duration covaried atypically. When categorizing accented speech, listeners rapidly down-weighted the secondary dimension (duration) while continuing to rely on the primary dimension (F0). This clarifies two core theoretical questions: 1) prosodic categories are signalled by multiple input acoustic dimensions and 2) perceptual cue weights for prosodic categories dynamically adapt to local regularities of speech input.

HighlightsO_LIProsodic categories are signalled by multiple acoustic dimensions.
C_LIO_LIThe influence of these dimensions flexibly adapts to changes in local speech input.
C_LIO_LIThis adaptive plasticity may help tune perception to atypical accented speech.
C_LIO_LISimilar learning models may account for segmental and suprasegmental flexibility.
C_LI



http://biorxiv.org/cgi/content/short/202...88v1?rss=1

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  Histone Deacetylase 2 (HDAC2) influences maturation and mitochondrial dynamics in
Posted by: BioRxiv - 4 hours ago - Forum: General Neuroscience talk - No Replies

Histone Deacetylase 2 (HDAC2) influences maturation and mitochondrial dynamics in


Histone deacetylase 2 (HDAC2) is a major HDAC protein in the adult brain and has been shown to regulate many neuronal genes. Aberrant expression of HDAC2 and subsequent dysregulation of neuronal gene expression is implicated in neurodegeneration and brain aging. Human induced pluripotent stem cell-derived neurons (hiPSC-Ns) are widely used models for studying neurodegenerative disease mechanisms, however the role of HDAC2 in hiPSC-N differentiation and maturation has not been explored. In this study, we show that levels of HDAC2 progressively decrease as hiPSCs are differentiated towards neurons. This suppression of HDAC2 inversely corresponds to an increase in neuron-specific isoforms of Endophilin-B1, a multifunctional protein involved in mitochondrial dynamics. Expression of neuron-specific isoforms of Endophilin-B1 are is accompanied by concomitant expression of a neuron-specific alternative splicing factor, SRRM4. Manipulation of HDAC2 and Endophilin-B1 using lentiviral approaches shows that knock-down of HDAC2 or overexpression of a neuron-specific Endophilin-B1 isoform promotes mitochondrial elongation and protects against cytotoxic stress in hiPSC-Ns, while HDAC2 knock-down specifically influences genes regulating mitochondrial dynamics and synaptogenesis. Furthermore, HDAC2 knock-down promotes enhanced mitochondrial respiration. Collectively, our study demonstrates a role for HDAC2 in hiPSC-neuronal differentiation, highlights neuron-specific isoforms of Endophilin-B1 as a marker of differentiating hiPSC-Ns, and demonstrates that HDAC2 regulates key neuronal and mitochondrial pathways in hiPSC-Ns.



http://biorxiv.org/cgi/content/short/202...56v1?rss=1

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  Distributed networks for auditory memory contribute differentially to recall preci
Posted by: BioRxiv - 4 hours ago - Forum: General Neuroscience talk - No Replies

Distributed networks for auditory memory contribute differentially to recall preci


The representations held in working memory are inherently noisy, but attention directed to relevant objects can effectively enhance their fidelity. While recent working memory models suggest that memory representations are distributed across sensory and cognitive-control brain regions, it remains unknown how multiple brain networks generate this attentional gain in fidelity. Here, we investigated the contributions of the distinct brain networks in maintaining and enhancing memory representations using psychophysical modeling and fMRI. Human listeners performed an auditory syllable pitch-discrimination task, in which they received valid (vs. neutral) retro-active cues to selectively attend to one of the two syllable categories maintained in memory. Valid (vs. neutral) retro-cues facilitated task performance, eliciting faster recall and enhanced recall precision of syllables in memory. Valid retro-cues also led to increased neural activation in fronto-parietal and cingulo-opercular networks, but not in sensory-specific superior temporal cortex. Multivariate pattern analysis as a proxy for representational fidelity in memory revealed that attended syllable objects were maintained in distributed areas across superior temporal, frontal, parietal, and sensorimotor brain areas. However, neural fidelity in left superior temporal sulcus and its enhancement through attention-to-memory best predicted the ensuing individual gain in recall precision of auditory objects from memory. These results demonstrate that maintaining versus attentionally enhancing auditory memory representations are functionally separable mechanisms across distributed brain regions.



http://biorxiv.org/cgi/content/short/202...43v1?rss=1

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  Local Shape Descriptors for Neuron Segmentation
Posted by: BioRxiv - 4 hours ago - Forum: General Neuroscience talk - No Replies

Local Shape Descriptors for Neuron Segmentation


We present a simple, yet effective, auxiliary learning task for the problem of neuron segmentation in electron microscopy volumes. The auxiliary task consists of the prediction of Local Shape Descriptors (LSDs), which we combine with conventional voxel-wise direct neighbor affinities for neuron boundary detection. The shape descriptors are designed to capture local statistics about the neuron to be segmented, such as diameter, elongation, and direction. On a large study comparing several existing methods across various specimen, imaging techniques, and resolutions, we find that auxiliary learning of LSDs consistently increases segmentation accuracy of affinity-based methods over a range of metrics. Furthermore, the addition of LSDs promotes affinity-based segmentation methods to be on par with the current state of the art for neuron segmentation (Flood-Filling Networks, FFN), while being two orders of magnitudes more efficient - a critical requirement for the processing of future petabyte-sized datasets. Implementations of the new auxiliary learning task, network architectures, training, prediction, and evaluation code, as well as the datasets used in this study are publicly available as a benchmark for future method contributions.



http://biorxiv.org/cgi/content/short/202...39v1?rss=1

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  Cholinergic signalling in the forebrain controls microglial phenotype and response
Posted by: BioRxiv - 4 hours ago - Forum: General Neuroscience talk - No Replies

Cholinergic signalling in the forebrain controls microglial phenotype and response


Loss of basal forebrain cholinergic projections occurs in Alzheimers disease, frontotemporal dementia and in aging. Moreover, nicotinic stimulation is anti-inflammatory in macrophages and microglia but how loss of basal forebrain acetylcholine impacts on microglial phenotype is poorly understood. Here we hypothesized that endogenous ACh maintains homeostatic microglial phenotype and that neurodegeneration-evoked loss of ACh tone, triggers microglial activation. Using the specific immunotoxin, mu-p75NTR-saporin, we performed partial lesions of the basal forebrain cholinergic nuclei, medial septum and ventral diagonal band. We examined microglial phenotype in the hippocampus, the major projection area for these nuclei, using bulk RNA preparations, Flow cytometry-sorted microglial cells, immunohistochemistry and ELISA to examine responses to cholinergic withdrawal and acute responses to subsequent systemic inflammation with LPS. Basal forebrain cholinergic degeneration elicited lasting activation of microglia in the hippocampus, showing suppression of Sall1 and persistent elevation of Trem2, Clec7a, Itgax and complement genes proportionate to Chat loss. These primed microglia showed exaggerated IL-1 beta responses to systemic LPS challenge. In normal animals LPS evoked acute increases in extracellular choline, a proxy for ACh release, and this response was lost in lesioned animals. Restoration of basal cholinergic signalling via serial treatments with the nicotinic agonist PNU282,987 resulted in reversion to the homeostatic microglial phenotype and prevented exaggerated responses to acute systemic inflammation. The data indicate that neurodegeneration-evoked loss of cholinergic tone, triggers microglial activation via impaired microglial nicotinic signalling and leaves these microglia more vulnerable to secondary inflammatory insults. The data have implications for neuroinflammation during aging and neurodegeneration and for responses to sepsis and systemic inflammation.



http://biorxiv.org/cgi/content/short/202...23v1?rss=1

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  Intracranial electrical stimulation alters meso-scale network integration as a fun
Posted by: BioRxiv - 4 hours ago - Forum: General Neuroscience talk - No Replies

Intracranial electrical stimulation alters meso-scale network integration as a fun


Human brain dynamics are organized into a multi-scale network structure that contains multiple tight-knit, meso-scale communities. Recent work has demonstrated that many psychological capacities, as well as impairments in cognitive function secondary to damage, can be mapped onto organizing principles at this mesoscopic scale. However, we still do not know the rules that govern the dynamic interactions between regions that are constrained by the topology of the broader network. In this preregistered study, we utilized a unique human dataset in which whole brain BOLD-fMRI activity was recorded simultaneously with intracranial electrical stimulation, to characterize the effects of direct neural stimulation on the dynamic reconfiguration of the broader network. Direct neural stimulation increased the extent to which the stimulation site's own mesoscale community integrated with the rest of the brain. Further, we found that these network changes depended on the topological role of the stimulation site itself: stimulating regions with high participation coefficients led to global integration, whereas stimulating sites with low participation coefficients integrated that regions' own community with the rest of the brain. These findings provide direct causal evidence for how network topology shapes and constrains inter-regional coordination, and suggest applications for targeted therapeutic interventions in patients with deep-brain stimulation.



http://biorxiv.org/cgi/content/short/202...41v1?rss=1

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  Development of a Semantically Related Emotional and Neutral Stimulus Set
Posted by: BioRxiv - 4 hours ago - Forum: General Neuroscience talk - No Replies

Development of a Semantically Related Emotional and Neutral Stimulus Set


When measuring memory performance for emotional and neutral stimuli many studies are confounded by not controlling for differential semantic relatedness between stimulus sets. This could lead to the misattribution of the cause of an emotional enhancement of memory effect (EEM), because differential semantic relatedness also contributes to the EEM. Participants rated static visual emotional and neutral scenes on measures of arousal, valence, and semantic relatedness. These measures were used to create a novel stimulus set, which, in addition to demonstrating significant differences in measures of valence and arousal, also controlled for within-set semantic relatedness; thus resolving a crucial issue that has not previously been addressed in the use of visual emotional stimuli. As an added advantage, the stimulus set developed here are controlled for measures of objective visual complexity, also implicated as confounding to the investigation of memory. This article introduces a collection of emotional and neutral colour images which can be organised flexibly according to experimental requirements. These stimuli are made freely available for non-commercial use within the scientific community.



http://biorxiv.org/cgi/content/short/202...07v1?rss=1

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Lightbulb Behavioral, Physiological, and Neural Signatures of Surprise during Naturalistic Spo
Posted by: Cell - 4 hours ago - Forum: Hot topics in neuroscience - No Replies

Behavioral, Physiological, and Neural Signatures of Surprise during Naturalistic Spo

Antony et al. derive a model tracking surprise during naturalistic basketball viewing and find many links to behavioral, physiological, and neural measures, including predicted changes in neural patterns. Their findings test and support key ideas in event segmentation theory and provide face validity for multiple laboratory findings about surprise.


https://www.cell.com/neuron/fulltext/S08...-9?rss=yes

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Lightbulb Subcircuits of Deep and Superficial CA1 Place Cells Support Efficient Spatial Coding
Posted by: Cell - 4 hours ago - Forum: Hot topics in neuroscience - No Replies

Subcircuits of Deep and Superficial CA1 Place Cells Support Efficient Spatial Coding

Sharif et al., demonstrated the existence of segregated hippocampal circuits for spatial coding across heterogeneous environments. Deep and superficial CA1 place cells used different codes for space depending on the availability of cues. A rapid switch between these two spatial coding modes was supported by the interaction between gamma inputs.


https://www.cell.com/neuron/fulltext/S08...-8?rss=yes

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Lightbulb A Visual Circuit Related to the Nucleus Reuniens for the Spatial-Memory-Promoting Ef
Posted by: Cell - 4 hours ago - Forum: Hot topics in neuroscience - No Replies

A Visual Circuit Related to the Nucleus Reuniens for the Spatial-Memory-Promoting Ef

Huang et al. identified a visual circuit related to the Re that regulates spatial memory. They demonstrate that the retina-vLGN/IGL-Re pathway mediates the spatial-memory-promoting effects of light treatment.


https://www.cell.com/neuron/fulltext/S08...-9?rss=yes

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