Brain structure & function
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The central extended amygdala (EAc) is a forebrain macrosystem which has been widely implicated in reward, fear, anxiety, and pain. Its two key structures, the lateral bed nucleus of the stria terminalis (BSTL) and the central nucleus of the amygdala (CeA), share similar mesoscale connectivity. However, it is not known whether they also share similar cell-specific neuronal circuits. ⋯ Within EAc, PKCδ+, but not SOM+ neurons, serve as the major source of inputs to the ventral BSTL and to the medial part of CeA. However, both cell types can be involved in mutual connections between BSTLD and CeL/C. These results unveil the pivotal positions of PKCδ+ and SOM+ neurons in organizing parallel cell-specific neuronal circuits within CeA and BSTL, but also between them, which further reinforce the notion of EAc as a structural and functional macrosystem.
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The basal forebrain (BF) contains at least three distinct populations of neurons (cholinergic, glutamatergic, and GABA-ergic) across its different regions (medial septum, diagonal band, magnocellular preoptic area, and substantia innominata). Much attention has focused on the BF's ascending projections to cortex, but less is known about descending projections to subcortical regions. ⋯ Additionally, glutamatergic and GABAergic BF neurons have distinct patterns of descending projections, while cholinergic descending projections are sparse. Considering the intensity of glutamatergic and GABAergic descending projections, the BF likely acts through subcortical targets to promote arousal, motivation, and other behaviors.
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Hevin, also known as SPARC-like 1, is a member of the secreted protein acidic and rich in cysteine family of matricellular proteins, which has been implicated in neuronal migration and synaptogenesis during development. Unlike previously characterized matricellular proteins, hevin remains strongly expressed in the adult brain in both astrocytes and neurons, but its precise pattern of expression is unknown. The present study provides the first systematic description of hevin mRNA distribution in the adult mouse brain. ⋯ Furthermore, hevin transcript was enriched in ribosomes of astrocytes and parvalbumin neurons providing a direct evidence of hevin mRNAs translation in these cell types. This study reveals the unique and complex expression profile of the matricellular protein hevin in the adult brain. This distribution is compatible with a role of hevin in astrocytic-mediated adult synaptic plasticity and in the regulation of network activity mediated by parvalbumin-expressing neurons.
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The semantic integration between gesture and speech (GSI) is mediated by the left posterior temporal sulcus/middle temporal gyrus (pSTS/MTG) and the left inferior frontal gyrus (IFG). Evidence from electroencephalography (EEG) suggests that oscillations in the alpha and beta bands may support processes at different stages of GSI. In the present study, we investigated the relationship between electrophysiological oscillations and blood-oxygen-level-dependent (BOLD) activity during GSI. ⋯ In time-window-based EEG-informed fMRI analyses, we further found a positive correlation between single-trial alpha power and BOLD signal in the left pSTS/MTG, the left IFG, and several sub-cortical regions. Moreover, the alpha-pSTS/MTG correlation was observed in an earlier time window in comparison to the alpha-IFG correlation, thus supporting a two-stage processing model of GSI. Our study shows that EEG-informed fMRI implies multiple roles of alpha oscillations during GSI, and that the method is a best candidate for multidimensional investigations on complex cognitive functions such as GSI.
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Personality is associated with variation in all kinds of mental faculties, including affective, social, executive, and memory functioning. The intrinsic dynamics of neural networks underlying these mental functions are reflected in their functional connectivity at rest (RSFC). We, therefore, aimed to probe whether connectivity in functional networks allows predicting individual scores of the five-factor personality model and potential gender differences thereof. ⋯ RSFC patterns of most networks, however, predicted personality traits only either in males or in females. Personality traits can be predicted by patterns of RSFC in specific functional brain networks, providing new insights into the neurobiology of personality. However, as most associations were gender-specific, RSFC-personality relations should not be considered independently of gender.