{"messages":[{"status":"ok","category":"all"}], "collection":[{"title":"Correlative light\u2013electron microscopy reveals fundamentally different axonal architectures for fast and modulatory transmission","authors":"Lee, K.;Sahlender, D.;Blanc, J.;Jorstad, A.;Gasselin, C.;Clerc-Rosset, S.;Markopoulos, F.;Petersen, C.;Holtmaat, A.;Knott, G.","author_corresponding":"Graham William Knott","author_corresponding_institution":"\u00c9cole Polytechnique F\u00e9d\u00e9rale de Lausanne","doi":"10.64898\/2026.08.11.744243","date":"2026-8-19","version":"1","type":"new results","license":"cc_by","category":"neuroscience","jatsxml":"https:\/\/www.biorxiv.org\/content\/early\/2026\/8-\/9\/2026.08.11.744243.source.xml","abstract":"We used correlative light and focused ion beam\u2013scanning electron microscopy (FIBSEM) to characterise the ultrastructural organisation of neuromodulatory axons in the upper layers of the adult mouse somatosensory cortex. Cholinergic projections from the basal forebrain and serotonergic axons from the raphe nucleus were reconstructed, enabling quantitative analysis of synapse and vesicle distribution. Consistent with prior work, these axons formed only small and morphologically indistinct synaptic specialisations. However, these sites contained only a small fraction of the total axonal vesicle population, which were instead distributed along their length and spatially uncoupled from identifiable synaptic contacts. In contrast to classical excitatory and inhibitory axons, where vesicles are tightly clustered at defined presynaptic release sites, this organisation indicates that synaptic release contributes only minimally to neuromodulator output. Instead, our data support a model in which acetylcholine and serotonin signalling is mediated predominantly through non-synaptic release, consistent with a spatially diffuse transmission across cortical microcircuits.","published":"NA","server":"bioRxiv"},{"title":"Hippocampal information topology breaks down in a mouse model of Alzheimer's disease","authors":"Yu, J.;Rajpal, H.;Go, M.;Schultz, S.","author_corresponding":"Simon R Schultz","author_corresponding_institution":"Imperial College London","doi":"10.64898\/2026.08.14.744888","date":"2026-8-19","version":"1","type":"new results","license":"cc_by_nc","category":"neuroscience","jatsxml":"https:\/\/www.biorxiv.org\/content\/early\/2026\/8-\/9\/2026.08.14.744888.source.xml","abstract":"Hippocampal spatial coding depends on coordination among neuronal assemblies, yet how network topology organises information processing across these assemblies, and how this is disrupted in disease, remain unknown. We apply Partial Information Decomposition to CA1 calcium imaging from young and aged wild-type and 5xFAD mice, quantifying redundant and synergistic information sharing within and between assemblies. In healthy CA1, between-assembly pairs carried more joint spatial information than within-assembly pairs, and this surplus was synergistic, establishing network topology as an organising principle of spatial coding. In aged 5xFAD CA1 this topological organisation broke down through two distinct routes: redundancy lost its topology dependence as modular assembly boundaries dissolved, and synergy lost context sensitivity during novel exploration, with the breakdown greatest where ageing and the 5xFAD genotype coincided. This functional decline was also accompanied by topological effects in the functional connectivity, where the genotype-age interaction resulted in reduced modularity, weighted clustering and small-worldness. Community-level emergence revealed a complementary cross-scale shift toward higher-order integration during ageing, which was reversed by the genotype-age interaction. We isolate the compounding effect of ageing in Alzheimer's disease as the driver of disruption in information processing and functional connectivity across neuronal assemblies in the mouse hippocampus.","published":"NA","server":"bioRxiv"},{"title":"The Effects of Teaching Emotion Words on Emotional Granularity, Emotion Regulation\/Dysregulation, and Satisfaction with Life","authors":"Fugate, J.;Kalmus, S.;Shcherbinin, H.;McKillip, M.;Shae, W.;Kasiska-Pettersen, J.","author_corresponding":"Jennifer Fugate","author_corresponding_institution":"Kansas City University","doi":"10.64898\/2026.08.12.744382","date":"2026-8-17","version":"1","type":"new results","license":"cc_by","category":"neuroscience","jatsxml":"https:\/\/www.biorxiv.org\/content\/early\/2026\/8-\/7\/2026.08.12.744382.source.xml","abstract":"\n                Emotional granularity (EG) has been associated with adaptive emotion regulation, psychological well-being, and reduced psychopathology. The present study examined whether teaching highly specific emotion words would increase EG and improve emotion regulation, emotional dysregulation, and well-being outcomes. A total of 95 adults were randomly assigned to either a 14-day emotion word training condition (n = 48) or a matched control word training condition (n = 47). Before and after training, participants completed assessments of word knowledge, self-reported and behavioral estimates of EG, emotion regulation, emotional dysregulation, and satisfaction with life. Mediation analyses evaluated whether changes in EG explained the relationship between increases in word knowledge variables and positive psychological outcomes. Participants in both emotion and control word conditions showed improvements in word knowledge variables after training, but only those in the emotion word group showed that increased emotion word usage was associated with higher EG (using the Range and Differentiation of Emotion Expression Scale, RDEES) and lower emotional dysregulation and reduced suppression. Those in the control group showed mixed effects for self-reported EG and outcomes. For neither group, however, were any of the effects mediated by either EG measurement. Furthermore, behavioral and self-report measures of EG were not significantly correlated, suggesting that they may capture distinct aspects of emotional functioning. These findings provide preliminary support for emotion vocabulary training as a low-cost intervention that may enhance emotional functioning and suggest that self-perceived EG may be more closely linked to adaptive outcomes.","published":"NA","server":"bioRxiv"},{"title":"Human iEEG recordings during audiovisual speech violations support and extend predictive routing models","authors":"Collado, J. V.; Nejat, H.; Brang, D.; Wasade, V. S.; Stacey, W. C.; Bastos, A. M.","author_corresponding":"Andre M Bastos","author_corresponding_institution":"Vanderbilt University","doi":"10.64898\/2026.10.30.760243","date":"2026-11-01","version":"1","type":"new results","license":"cc_by","category":"neuroscience","jatsxml":"https:\/\/www.biorxiv.org\/content\/early\/2026\/11\/01\/2026.10.30.760243.source.xml","abstract":"Rather than constantly reconstructing the world solely through sensory input, predictive processing theories posit that the brain utilizes predictions maintained as internal representations to guide sensory processing. An emerging model, predictive routing, proposes that an interplay between neuronal gamma (40-150 Hz) and alpha-beta (10-30 Hz) rhythms implements a dynamic mechanism for predictive processing. Namely, predictions enhance alpha-beta oscillations that suppress gamma activity during the processing of predicted inputs. While this model is supported by animal studies, its validity has not been fully explored within the human brain. The present study addresses this by leveraging human intracranial EEG (iEEG) recordings across superior temporal and prefrontal\/premotor areas of seven presurgical epilepsy patients during an audiovisual speech paradigm. We calculated iEEG power in the theta, alpha-beta, and high gamma bands during simple auditory deviance, multisensory integration, and a condition where an incongruent visual cue (lip movements) clashed with an auditory stimulus (a syllable), creating audiovisual incongruence that can elicit the McGurk illusion. Results revealed increased high-gamma and decreased alpha-beta power in the superior temporal cortex in response to auditory deviance and the McGurk condition, while frontal areas, despite reflecting a similar decrease in alpha-beta power, did not present this high gamma prediction error signal. Instead, the theta band revealed a strong prediction error signal in the McGurk condition, consistent with theories on the role of theta in reorganizing cortical networks. These results both support and extend existing predictive routing models for human-specific forms of predictive processing.","published":"NA","server":"bioRxiv"},{"title":"The human-specific gene FRMPD2B couples postnatal experience to the expansion of cortical connectivity","authors":"Christopoulou, E.; Zamith, J.; Bonadonna, P.; Rivero Romano, M.; Vaudin, M.; Nguyen, W.; Brunet, C.; Blugeon, C.; Lemoine, S.; Giudicelli, F.; Baffet, A.; Charrier, C.","author_corresponding":"Cecile Charrier","author_corresponding_institution":"Inserm","doi":"10.64898\/2026.10.30.763086","date":"2026-11-01","version":"1","type":"new results","license":"cc_by_nc","category":"neuroscience","jatsxml":"https:\/\/www.biorxiv.org\/content\/early\/2026\/11\/01\/2026.10.30.763086.source.xml","abstract":"The human neocortex is characterized by its uniquely prolonged postnatal developmental period during which experience sculpts neuronal circuits, a process essential to human cognitive abilities. Yet whether human-specific genetic innovations have shaped the activity-dependent mechanisms regulating circuit assembly remains unknown. Here, we identify the human-specific gene FRMPD2B as an activity- and experience-regulated modifier of cortical connectivity. FRMPD2B is primarily expressed in cortico-cortical projection neurons postnatally and throughout childhood. It promotes dendritic, axonal and synaptic development, and is required for proper morphogenesis in xenotransplanted human cortical neurons. FRMPD2B expression is bidirectionally regulated by neuronal activity and experience. This activity-responsiveness was gained after FRMPD2B arose through partial gene duplication, when a retrotransposon insertion remodeled its promoter. Our findings highlight how a series of genetic innovations have led to the emergence of a human-specific activity-regulated developmental program through which postnatal experience drives cortical connectivity expansion, linking genome evolution to human brain plasticity.","published":"NA","server":"bioRxiv"}]}